This is just a list of anime I think everyone should watch at least once:

• 5 Centimeters Per Second
• Akira
• Aoi Bungaku
• Arakawa Under the Bridge
• Cat Soup
• Cowboy Bebop
• Eden of the East
• Grave of the Fireflies
• Great Teacher Onizuka
• Full Metal Panic? Fumoffu
• Genshiken
• Haibane Renmei
• Kaiba
• La Maison en Petits Cubes
• Mind Game
• Mononoke
• Monster
• Mōryō no Hako
• Mushi-Shi
• Nausicaä of the Valley of the Wind
• Paprika
• Paranoia Agent
• Planetes
• Princess Mononoke
• Sakamichi no Apollon
• Serial Experiments Lain
• Spirited Away
• Tekkonkinkreet
• The Tatami Galaxy
• UN-GO
• Welcome to the NHK
• Whisper of the Heart
• Voices of a Distant Star