huge sci fi geek, so surprised i haven't tripped on this thread before. for my money, here are my tops:

Serenity
Donnie Darko
Children of Men
Eternal Sunshine of the Spotless Mind
Empire Strikes Back
Star Wars
Return of the Jedi
The Matrix
Fifth Element
even numbered Star Trek films
Star Trek: First Contact
Ghostbusters
Back to the Future
ET
Close Encounters of a Third Kind
Jurassic Park
Brazil
12 Monkeys
Terminator
T2
Men in Black
Blade Runner
Alien
Aliens
Alien 3
The Iron Giant
Adventures of Buckaroo Banzai Across the 8th Dimension
Independence Day
Pitch Black

(yes, i do enjoy some cheese with my sci-fi from time to time. )

for sci fi TV:

Firefly
Battlestar Galactica (current)
Lost
Doctor Who
Cowboy Bebop
Star Trek
Star Trek: The Next Generation
Star Trek: Deep Space Nine
Heroes
The 4400
Futurama

just to name a few.

as for graphic novels being adapted soon, Y the Last Man seems on the fast track. Neil Gaiman is apparently well on the way to getting his adaptation of his own Death: The High Cost of Living made. Hellboy sequel coming soon, and i'm so psyched about that! and of course the long awaited (and in some circles slightly dreaded) adaptation of Alan Moore and Dave Gibbons' Watchmen, which i'm hoping will be good. oh, and The Dark Knight which looks excellent. i think those are the only ones in development that i'm really looking forward to right now. oh, and Brian Michael Bendis' Jinx is supposedly still coming out at some point with Charlize Theron as the title character...and Mark Millar's Wanted, though some of what i've heard makes a bit hesitant towards it. we'll see. Grant Morrison and Frank Quitely's We3 has been optioned by New Line, i believe...but i think they're still drafting a screenplay.