Batman Animated Series renowned for its synthesis of 50+ years of Batman stories, its "dark deco" timeless style, its peerless voice acting and music orchestration, its often thematically dark material(or at least handled with a sense of realism), its classical film influences and cinematic three act structure. There's over a 100 episodes, and I say about 50 are well worth watching. The show gets more consistently good as it goes along and they learn what works and what doesn't.
Excellent - The creme de le creme, the masterpieces, some of the best Batman stories in any medium
Two-Face
Beware the Gray Ghost
The Laughing Fish
Over the Edge
Read My Lips
Very Good - Exemplary episodes with a strong combination of animation, characterization, and design
Bullet for Bullock
Harley's Holiday
Critters (Controversial, but I love it)
Growing Pains
The Man Who Killed Batman
Joker's Favor
Beware the Creeper
Avatar
Deep Freeze
Catwalk
Mad Love
World's Finest(Batman/Superman 3-part crossover)
Never Fear
Heart of Ice
Perchance to Dream
Robin's Reckoning(the first part is excellent, second one is just aight)
See No Evil
Almost Got 'Em
Legends of the Dark Knight
Second Chance
On Leather Wings
Vendetta
House & Garden
Good - Solid stories that even amongst their flaws succeed as entertaining superhero drama
Mask of the Phantasm
Heart of Steel
His Silicon Soul
The Clock King
Harlequinade
Showdown
Joker's Millions
Double Talk
The Demon's Quest
Mystery of the Batwoman
Time Out of Joint
Judgment Day
Fear of Victory
Mudslide
Harley & Ivy
Knight Time(Superman episode where he takes over for Batman)
The Ultimate Thrill
Bane
Riddler's Reform
Fire from Olympus
Holiday's Knights
Okay - Shaky concepts, cliche-filled scripts, weak animation, and/or pedestrian plots. These episodes have their joys, but only in spurts
Mad as a Hatter(an EXCELLENT script and vocal performance let down by terrible animation)
Cult of the Cat
Joker's Wild
Mean Seasons
You Scratch My Back
Trial
If You're So Smart Why Aren't You Rich?
Baby-Doll
Day of the Samurai
Feat of Clay
Chemistry
Sub-Zero
Mean Seasons
What is Reality?
Eh - Totally forgettable episodes, not good enough to recommend but not so bad as if to offend
Dreams in Darkness
Appointment in Crime Alley
Batgirl Returns
Be a Clown
Christmas with the Joker
Cape and Cowl Conspiracy
Blind as a Bat
Sins of the Father
The Strange Secret of Bruce Wayne
Torch Song
P.O.V.
Paging the Crime Doctor
Night of the Ninja
Off Balance
Deep Freeze
Sideshow
Old Wounds
Demon Reborn
Zatanna
Love is a Croc
Pretty Poison
Make 'Em Laugh
Lock-Up
Girls Night Out
Birds of a Feather
The Worry Men
It's Never Too Late
Awful - Lousy animation, shrill melodramatics, boring action setpieces. These episodes should be avoided
I Am The Night(controversial, but I hate it)
The Demon Within
The Terrible Trio
Animal Act
Moon of the Wolf
The Underdwellers
Tyger Tyger
The Last Laugh
The Mechanic
Crap - The worst of the worst. Episodes that should be erased from time.
I've Got Batman in my Basement
Cat Scratch Fever
Eternal Youth
The Forgotten