You need some real classics. So I'll add some old school stuff with a few more recent titles.

Galaxy Express 999
Captain Herlock (there is a awesome recent series to this)
Tokyo Babylon (Japanese please, the english dub is pretty bad)
Chobits
X/1999 (Watch the anime or movies but please read the manga as its the best version despite not being finished)
Haibane Renmei
Voices of a Distant Star
Robot Carnival
Casshan
3x3 Eyes
Bubblegum Crisis
Dominion Tank Police
Ranma 1/2
Maison Ikkoku
Kare Kano (anime is okay, manga is better)
Witch Hunter Robin
Wolf's Rain
Tenchi Muyo! Ryo-Ohki (the original OVA is awesome, the rest of the series are good except Tenchi in Tokyo which should be avoided at all cost, definetly watch the movies though)
Green Legend Ran
Phantom Quest Corps
Jubei Chan
El Hazard
Ah! My Goddess
Video Girl Ai
Irresponsible Captain Tylor
Monster
Black Lagoon
Metropolis
Karas
Azumonga Daioh
Big O
Anything by Hayao Miyizaki and Satoshi Kon and of course...


Super Dimensional Fortress Macross

Also watch the movie Macross: Do You Remember Love? and Macross Plus

Now get to work on your anime homework