I made a thread earlier with these recommendations. I don't know what happened to it but I did not see this thread before so time to repost it!
http://lbp.me/v/06y4zb
A MUST PLAY. A top down dark fantasy hack and slash akin to Demon's Souls (even down to the lock on). Fun, challenging, and completely co-op for up to 4 players.
http://lbp.me/v/z5g597
A must play as well! This is another dark fantasy that was done earlier than the one before. The level is simpler and there is no lock on but the gameplay is great and completely worth the playthrough.
http://lbp.me/v/x3s244
Shoot em up top down game in a large arena with environmental hazards. Best played with 3-4 players.
http://lbp.me/v/0mxe66
Gundam Wing Survival Challenge. Hack and slash challenge as you try to survival against large amounts of a variety of enemies and bosses such as the Tallgeese. Updated soon with more mechs to play than the Wing Gundam.
http://lbp.me/v/0f2sw-
A Malevolent Tale. The story of how the characters from LBP1 got into Eve's Asylum. This level begins with a fairly lengthy opening cutscene but after it the game itself spans 4-5 whole levels and is arguably better than the campaign levels themselves. One of my favorites.
http://lbp.me/v/zr7we9
Crimson Lance: Genesis. Top down co-op PvE mech game inspired by Chromehounds. Best played with buddies but fully capable of being done with one person. Do the tutorial level on the person's Earth.
http://lbp.me/v/0bjdwc
A collection of level links to a guy's most recommended levels. A good start for finding many other games to play.
http://lbp.me/v/w0h63v
Stereo/Mono 2. A rhythm based platformer. Fantastic aesthetic.
http://lbp.me/v/yfh2ms
Obscurity. One of my favorite levels for just Part 1 of the story. Funny dialogue, inventive puzzles, and honestly a fun game.
http://lbp.me/v/y3t9gs
Virtue vs. Vices battle arena. Works well with 2 v. 2 games. Class based gameplay revolving around handling elements and player skills. A top down class based fighter. Prepare to do a tutorial before it though.
http://lbp.me/v/zknred
Absolutely fantasy aesthetic.
Mt. Kalan. One of my favorites.
http://lbp.me/v/z28y6j
A fun little video called Ninja Baby. A fun, short, and simple comedy video. Watch it. One of my favorites.
http://lbp.me/v/z28y6j
A versus side scrolling game with proper sword and shield mechanics! Bring friends! Check this guy's levels for singleplayer sword and shield games.
http://lbp.me/v/xgh6jv
Switch between side scrolling and top down platforming at will to solve puzzles!
http://lbp.me/v/y6xcxg
Honestly just a very fun platforming game. I recommend everything by Lockstitch as a platformer. He's fantastic.
http://lbp.me/v/xpq4qe
A horror game that actually does a good job! Comes in two parts. The second part kind of ruins it but the first part and the end of the second is definitely worth the playthrough.