Main recommendations list:

1. Legend of the Galactic Heroes (info)
2. Gundam

The franchise is praiseworthy as a whole but my favourites, and therefore objectively good ones, are:

• Mobile Suit Gundam MS IGLOO (realism)
• Mobile Suit Gundam
• Mobile Suit Gundam 0080: War in the Pocket
• Mobile Suit Zeta Gundam
• Mobile Suit Gundam Unicorn (but animation :[)
• ∀ Gundam
• Gundam 00, if you discount the second season and the movie woops 

3. Revolutionary Girl Utena
4. Monster
5. Neon Genesis Evangelion

Recommendation list not exhaustive omfg:

• 5 Centimetres per Second
• Angel’s Egg
• Black Lagoon
• Bunny Drop (ウサギドロップ) 
• Charcoal Feather Federation
• Cromartie High School
• Darker than BLACK - 黒の契約者- 
• Death Note
• Electromagnetic Girlfriend
• Gankutsuou
• Ghost in the Shell (all)
• Kaiji (all) 
• Kids on the Slope
• La maison en petits cubes
• Last Exile
• Mawaru Penguindrum
• Millennium Actress
• Nana
• Ouran High School Host Club
• Outlaw Star
• Paradise Kiss
• Paranoia Agent
• Perfect Blue
• Ponyo on the Cliff by the Sea
• Princess Jellyfish
• Kimi ni Todoke
• Rose of Versailles
• Samurai X: Trust and Betrayal
• Serial Experiments Lain
• She and Her Cat
• The Tatami Galaxy
• Texhnolyze
• The Girl Who Leapt Through Time
• Time of Eve
• Tokyo Magnitude 8.0
• Welcome to the NHK!