A lot of great anime listed, including many I'd say are contenders for the best of all time.
Some I wouldn't say are the best of all time but very good that I didn't notice skimming the pages...
Tenjou Tenge - Action/fighting fans won't want to miss this, of the the most epic beatings ever http://www.youtube.com/watch?v=d7uqV...eature=related
Shuffle! - Just when you think its another harem anime you get hit with a serious twist.
Gantz - If only they continued it and didn't make up an ending to cut it short
D.N. Angel - A bit of an older selection but a good one.
Tora Dora - Another slice of life comedy but pretty well done and backed by a good story.
Chobits - Falls into the old school classics category, starts out cute then develops interesting plot twists
Shiki - Very interesting anime wrapped in mystery and suspense
and I'll just stop there before I end up listing way too many.