I haven't played rpg's as much in recent years, but I used to play them a lot. My list is mostly going to be older games probably. Let's get started.
1. (HIGHLIGHT)
Final Fantasy VI - I sometimes hear people that don't like rpg's say things like, "I don't play Final Fantasy type games". When a series is used by people who don't know the genre to describe that entire genre, you know it's essential.
6 is my favorite mainline FF. I love that it has an ensemble cast with no real "main" character. Despite such a large cast (14 playable characters), somehow all of the playable characters besides the two optional hidden ones end up with plenty of development that makes the player get attached to them. Hell, that could be said of some of the NPC's even (General Leo is awesome). The game's villain is also really well done, a character you love to hate, and even has an iconic laugh sound effect. I also love the game's story for taking a turn i'd never seen before, rarely since, and never done again in quite the same manner, to my knowledge.
Mechanics wise, i also really liked that each character has a battle skill unique to them. To me, fully customizable characters lose some of their personality. FF6 also has a fun gameplay feature that i've sadly never seen repeated; several dungeons have you take multiple parties and switch back and forth between them in order to progress.
And let us not forget the intensely emotive score that really contributes to how atmospheric FF6 is. Nobuo Uematsu is a genius.
FF6 is also very replayable, as not only does the Esper system provide some character customization, but the large cast means you can play through much of the game with a completely different party than you did on a previous playthrough. On top of that, there are hidden secrets and ways to play you might not even discover on your own. For example, I had no idea Wind God Gau was a thing until i read about it on a forum, years after I had played through the game multiple times already. I would recommend your first playthrough without reading about these things of course.
2. (UNDERRATED)
SaGa Frontier - Another rpg from the golden era of Squaresoft that has sadly been overlooked by many, this has multiple "main" characters to choose from when you start the game, each with their own unique scenario to play through. They do cross each others' paths though, and sometimes join each others' parties. The cast of characters is wide and interesting, there's a young man who can turn into a superhero, a robot, a beast boy, and a mage, among others. There are also more playable characters aside from the main cast, some of whom are pretty cool. There's this one drunken ronin who is a total badass, when you play the robot's scenario you will see what i mean. There are a total of 40 PCs, though 2 aren't normally recruitable.
The gameplay is deep as the mechanics are complex, but you don't have to understand them all to complete the game. There are tons of physical skills to learn, which are gained when using basic attacks or skills from the same school in a mechanic called Sparking. Some skills also change into more powerful versions with different names when used under the right conditions. Many of the physical skills can also become Combo attacks when party members use them in the right order. There are also magical spells to learn from varied schools, though there aren't as many spells as there are physical skills.
SaGa Frontier is also very replayable, as unless you spend a lot of time on unnecessary grinding you won't Spark all abilities or see all Combos in a single playthrough.
3.
Shin Megami Tensei: Nocturne - There isn't much I can say about this that hasn't already been said. This has the best turn-based battle system of all time, and it is just as harsh and unforgiving as the story of the game. Speaking of the story, it's a dark, refreshing taste of originality that throws binary morality out the window and explores deeper philosophical themes. The only thing keeping this from being my personal GOAT is I don't really care for the SMT aesthetic, and the cyberpunk metal soundtrack, while enjoyable, doesn't hold a candle to the masterpieces in other games, such as any of Uetmatsu's work. But I can't stress enough how good the gameplay is here. You don't understand how good turn-based jrpg style combat can be until you play a MegaTen game with the Press Turn system.
4.
Shadowrun: Dragonfall - I really dig the Shadowrun universe. It's a dark, gritty cyberpunk era, yet swords and sorcery have also returned to the world along with nonhuman races. The storytelling is top notch and the cast of characters is great. It also features morally ambiguous choices (noticing a trend in my tastes yet?), that actually have significant effect on the story.
5.
Star Wars: Knights of the Old Republic II - This game improved on everything its predecessor did, though it was sadly rushed in development and shipped with a lot of cut content. I'm happy to hear that there are mods to restore that content available now. As others have said, the writing here is top notch, the crew characters actually respond dynamically to your choices, and Kreia is a phenomenal character.
6.
Suikoden III - I absolutely love this game. The large cast of characters, the multiple scenarios, the base building, the unique and fun battle system that involves pairing up your party members (sometimes combining them into a single mounted unit!), this was just a joy to play.
7.
Ys: The Oath in Felghana - Ys games are straightforward balls-to-the-wall action rpgs with kickass metal soundtracks. If you like intense, hectic gameplay accompanied by
shredding guitar riffs, you will love them. If that doesn't sound appealing to you, then these games aren't for you.
8.
Final Fantasy Tactics - I tried to only have 1 entry per series. I made an exception for FFTactics because it's so different from the mainline entries. The tactical gameplay involving positioning and terrain is great, and the job system allows for tons of customization fun. The soundtrack is marvelous. But the story filled with political intrigue, corruption, and tragedy, met with courageous, unflinching determination, is where this game truly shines. The psp version, War of the Lions, has the vastly improved translation.
9.
Tales of Vesperia - Tales games take the traditional jrpg formula of linear story with sidequests and mini-games, but mix in real-time combat (with a pause menu for selecting spells/items) that is an absolute blast. You can also control any character in your party, some of whom have very different play styles, and have the rest controlled by customizable AI. I've loved every Tales game I played for the gameplay alone, but Vesperia has a special place in my heart for finally giving me the protagonist i've always wanted. Yuri Lowell is good man with a strong sense of justice. He recognizes that law systems usually fail against people in power, and does not hesitate to bring such people to vigilante justice instead when necessary.
10.
Fire Emblem: Path of Radiance - Fire Emblem games' simple yet strategic gameplay will hook you and have you sink dozens, maybe hundreds, of hours into them. I spent almost every available moment of leisure time i had on this one over the course of a summer, with its first-in-the-series bonus exp system.
Honorable Mentions
11.
Valkyria Chronicles - Strategic gameplay reminiscent of Fire Emblem with 3D movement and FPS/TPS shooting. And grenades and tanks! The story and characters are also touching.
12.
Castlevania: Symphony of the Night - The game that spawned an entire sub-genre known as Metroidvanias. I would call this a platformer rpg, but I admit Metroidvania has a nicer ring to it. This has a wonderful soundtrack that mixes gothic orchestral tones with metal riffs, great action platformer gameplay, a level system with experience and stat gains, magic spells (performed by entering commands similar to those used for 2D Fighting game special moves), and loads of equipment including random enemy drops. The many different weapons (and shields, which are also equipped in one of the hand slots) provide different playstyles, and you won't see them all in one playthrough unless you spend many hours farming enemies for their rare drops. Some of them even have special moves, performed with 2D fighter commands like spells, such as teleporting horizontally and attacking in the other direction (good for attacking enemies from behind). One of my favorite weapons that I haven't seen many talk about is the Chakram, which throws out a ring projectile that returns. Each Chakram is actually a pair though, so you can throw a second projectile while the first is in the air. If you equip a Chakram in both hands, you have 4 projectiles to throw that you can pretty much spam non-stop. Very strong without being gamebreaking like the Crissaegrim.
13.
Borderlands 2 - The Borderlands series is like the movie The Road Warrior turned into a tps action rpg, but with futuristic sci fi tech added along with a healthy dose of humor. Borderlands 2 is another case where it improved on everything its predecessor did.
14.
Kingdom Hearts I haven't been a big Disney fan since elementary school, but this cross over blew my mind with how good it was. I love the combat in this series. 2 actually improves the combat even further, but I chose 1 as the series' rep due to the godawful intro segment in 2. Birth by Sleep on the psp is also great, haven't played any of the other games yet.
15.
Disgaea - Disgaea takes the strategic gameplay of FFT and goes even deeper with it. Then it adds in tons of content to experience it with thanks to the never-ending Item World. Prepare to lose months of your life if you go deep with this game. Disgaea differs from FFT in that it's much less serious and filled with wacky humor.
16.
Chrono Trigger - I think enough has been said about this game, but I couldn't exclude it from a list of essential rpg's.
17.
Secret of Mana - this was the first Squaresoft game i ever played and the game that got me into rpg's. The title screen intro and music immediately shows how beautiful and charming this game is. I am very excited for the remake!
18.
Breath of Fire 3 - The Breath of Fire games i've played are kind of basic jrpg's, but they have their own style and the series deserves to be on an essentials list i think. It was a toss up between 2 and 3 for which one I chose here. I should note that i've yet to play Dragon Quarter, as somewhat negative reviews and an abundance of games to play at the time turned me away from it, but after reading some of the praise for it in this thread I definitely want to play it now.
19.
Skies of Arcadia - Skies of Arcadia is bursting with charm and the gameplay is fun. It's been years since I played so I unfortunately can't remember much more than that.
20.
Wild ARMs - The anime intro with the Cowboy Western type music sets the stage for this fun game with it's unique Western theme. Great puzzles!
I wanted to include Lufia II on my list but ran out of room
--VOTE INFO START—
<FULL POINT GAMES – 2 points>
{HIGHLIGHT – 3 points} Final Fantasy VI
{UNDERRATED – 4 points} SaGa Frontier
Shin Megami Tensei: Nocturne
Shadowrun: Dragonfall
Star Wars: Knights of the Old Republic II
Suikoden III
Ys: The Oath in Felghana
Final Fantasy Tactics
Tales of Vesperia
Fire Emblem: Path of Radiance
<HONORABLE MENTIONS – 1 point>
Valkyria Chronicles
Castlevania: Symphony of the Night
Borderlands 2
Kingdom Hearts
Disgaea
Chrono Trigger
Secret of Mana
Breath of Fire 3
Skies of Arcadia
Wild ARMs
--VOTE INFO END--