It's tough to keep track of what is still in print, so apologies if some of these are hard to find.
Arcadia of My Youth (the original Captain Harlock TV series is a classic too, but that's 70s)
Bubblegum Crisis (don't bother with Crash or 2040)
City Hunter (the movies are pretty good, but the formula works best at TV episode length)
Fist of the North Star (try the movie first, and then the TV series if you want more)
Goshogun: The Time Etranger
Gunbuster
Gundam movie trilogy
Zeta Gundam
Patlabor (TV, OAVs and movies)
Project A-ko (just the first movie; the quality of the sequels drops off a cliff)
Royal Space Force
Urusei Yatsura (TV series and movies 1, 2, and 4 are the best)
Vampire Hunter D (the 2000 movie Bloodlust is better, but the old OAV has its charms)
Space Adventure Cobra
Dominion Tank Police
Dragon Ball Z (Kai is the best version, since it chops out the massive amount of filler)
Galaxy Express 999 (definitely the first movie, but that's all I've seen)
Locke the Superman (if you get the Discotek DVD, it has one of the most gloriously cheesy English dubs ever, but that's not on the Blu-ray)
Lupin the 3rd: Mystery of Mamo (this is the only Lupin I really enjoy, but I'm in the minority there)
Macross: Do You Remember Love? (Its only official western release was a UK VHS unfortunately)
Maison Ikkoku (the DVDs cost a fortune now. The original manga is great too)
They Were Eleven
Ulysses 31
Venus Wars
3x3 Eyes (the first OAV series is great, the second is a mess)
Fire Tripper
Mermaid Forest