I would have to say..

Hitchcock (of course)
Kubrick
David Lynch
Wong Kar Wai
The Coen Brothers
Wes Anderson

Despite a few blips (Indy 4, Jurassic Park 2) Spielberg is in my top list due to his sheer versatility.
The Coen's go without saying (again, despite a couple of blips)
PT Anderson
Wes Anderson
(but not Paul WS Anderson :) )
Kevin Smith
Hitchcock
David Fincher
Chris Nolan
Sam Raimi
Baz Luhrman
James Cameron (for sheer spectacle alone)
Guillermo Del Toro
Paul Verhoven (I'll pretend Showgirls never happened)
Andrew Stanton (he may make animated films, but Nemo and Wall-E are two of the finest animated films ever and have the ability to move me to tears)


I'm sure there are more.....well, looking at my DVD collection there must be :)

Eastwood
Tarantino
Darabont
Carpenter

David Fincher - Fight Club, Se7en, Panic Room Zodiac, The Game. And Vogue -lol!
Alfred Hitchcock - far too many to mention - Notably Rope
Joel Schumacher - Lost Boys, Falling Down A time to kill Phone Booth
Rob Reiner - When Harry met Sally, Misery, Princess Bride, Stand by me amongst others.
Spielberg -far too many to mention but notably Indi films and Minority Report

But I will always watch a Christopher Nolan, Shymalan, Ridley scott, Scorsese and think it's a shame Roger Avary works as little as he does.

Erm... Christopher Nolan (Memento was supercool)
Coen brothers (what can I say? I am obviously a sheep)
Zhang Yimou (Hero, House of the Flying Daggers, Beijing Olympic Opening Ceremony)
Yeah, Spielberg has done some incredible films... and so many!
Er...
Um...
Tarantino's earlier stuff is way better than the later stuff


OH JESUS! Almost forgot Tim Burton!

I forgot Time Burton too!

Also, I've only watched a few of his films but each one has been breath-taking - Ingmar Bergman.