There aren't too many series that I've seen or would recommend that aren't licensed, or are at least being subbed at a reasonable pace that you could manage to show most of it before you graduate. But here's what I would recommend. Hope it helps!
Hanaukyo Maid Tai - The original series, not the remake that was recently licensed. More gag driven with a healthy dose of fan service. Also, focusing on chara development more than story. A better series than La Verite IMHO.
Kanon - I am suprised that this series has still not been licensed. One of the first of several non-hentai anime based on hentai games. It is a very touching love triangle type of story. A fan classic!
Lupin III - You've seen the second series, as broadcasted on Cartoon Network. Now watch the original series in all it's glory. Lupin and the gang in all their rambunctious, 70s glory.
Macross Zero - Whether or not you're familar with the original Macross TV series (AKA first season of Robotech), this 5-episode prequel OVA is not to be missed. Mind-blowing animation, writing and voice acting.
Mahou Sensei Negima - Based on the current manga in serialization by Ken "Love Hina" Akamatsu. A 12-year old boy from a wizard school in Wales must complete his magical education..... by teaching english at an all-girls school in Japan. 'nuff said
Momoiro Sisters - In the vein of Ebichu and Excel Saga, a "short-episode" series that focuses on the sex lives (or lack there of) of a pair of sisters (one in high school, the other an office lady) and their peers. Wrongness insues. Not for the squeemish. You have been warned.
Pita Ten - Another series that, quite frankly, I'm shocked that it has't been licesned yet. A cute and fluffy anime about an clumsy angel, a kind-hearted demon and their human friends.
St. Luminous Mission High School - One of my most favorite anime of all time. If you love mystery, suspense and intrigue then this is the series for you. A high school student suddenly finds that he has inherited a position from his recently deceased grandfather....
that of the chairman of an all-girls high school. But there will be no time for romantic hijinks, if he is to discover the reason for a recent string of disappearences before the entire student body disappears.
Tenshi na Konamaiki - AKA Cheeky Angel. Anime just wouldn't be anime without slapstick violence and gender-bending hijinks. With the voice of Megumi Hayashibara in the lead, you can't go wrong with this series. They did a great job of making the manga "come alive" so to speak. Including the chara's comical expressions. Male harem anime will never quite be the same (or was it ever?).