ok, i wont say best, but good ones are:

action: Naruto, Full Metal Panic, Trigun, Rurouni Kenshin, Get Backers, Hellsing, Read or Die OVA, Tenjo Tenge, Samurai Champloo, Shadow Skill, Shura no Toki, Scryed, Airmaster, Gantz

action/drama : Cowboy Bebop, Outlaw Star, Wolf's Rain, Yugo the Negotiator, Monster, Konjiki no Gash Bell,

comedy: Full metal Panic:fumoffu, Golden Boy, Green Green TV, Great Teacher Onizuka

Dramedy (drama/comedy): Ai yori aoshi/enishi, Onegai Teacher, Onegai Twins, Ultra Maniac, DNA^2, Midori no Hibi, Gokusen

i know its a lot but i still feel like im only scratching the surface lol, i watch a lot of anime and ive seen all of most of these series, i know theres more but thats a good start for an otaku in the making [img]i/expressions/face-icon-small-happy.gif[/img]

must see anime:
Great Teacher Onizuka - hilarious, one of the funniest series ever
Golden Boy - ultra hilarious, keep a bucket in ur room or u may wet urself
Full Metal Panic: Fumoffu - PURE HILARITY, funniest series i've ever seen period
Green Green Tv - hilarious and perverse, beware the all male gym orgy and the bear rape....
Trigun - classic, action/westernish anime
Get Backers - a well balanced series, some comedy, some drama, pretty good action

ps - almost forgot to put in Full Metal Alchemist, and i know im forgettin so much more, but oh well lol