looking through these...I...recognize a few of them. I REALLY wanted to watch slayer but only saw the first few episodes on telemundo (the spanish channel) but it was very cute/interesting.
Lupin the 3 is a great show (thanks Adult Swim!)
Rurouni Kenshin was cool, and a sequel series if I remember correctly from samuri X (didnt watch samurai X) but saw kenshin on Toonami, was entertaining.
Trigun is cool (honestly mash up anything sci-fi with a spaghetti western and I'll watch it)
Outlaw Star (see above)
Cowboy BeeBop (best anime I ever watched, ever in the history of everness. Also see above)
8th MS team (Ive touched on it before, well worth it!)
Samurai Champloo (was interesting and was pretty much like Cowboy Beebop but in Shogun Japan)
FLCL (strange is too light a word for this anime which I saw as an allegory for adolescence)
Big O (batman with a mech, good but got really weird closer to the end with a total mind fuck episode that made me loose interest)
edit: Okay saw this and had to share. Can you name all the references?