What would it be and why? (assume they really work like in the movies rather than just being painted wood and special effects)
For me I think it'd have to be the Imperial Lambda class shuttle from Return Of The Jedi. Its a moderately big ship but not so big that I'd need a large crew, the variable geometry wings and beaked cockpit design is pure class, it looks like it'd have reasonably decent cargo space so I could transport pretty much anything I'd be likely to need, its got weapons and its hyperspace capable so I could see other star systems

I would want the money that appears on countless game shows, so I can buy more games. Nuff said. :D

Holodeck.

Jason Vorheese as my Best Friend. Piss me off now!

Above
Only I'd have it as a part of an Excelsior class cruiser

I say Bender! Since he's technically not a person but a robot!
That should classify "him" as an item shouldnt it :P

The TARDIS from Doctor Who. A time machine more practical and easier to fuel than a DeLorean.

OKay, his story for dummies:
Went out on the lake on a canoe.
Camp Counselors watching him were having sex while he *Drowned*.
Mom went nuts and killed counselors.
A few years later, above happens but she gets decapitated.
Turns out Jason never drowned, but instead lived in the woods.
Did what his mom did.
And technically since he "dies" so much, he is a corpse, therefore making him an item.
=/

I'd go for something totally useless, like Van Helsing's boots. Worthless, stinky and probably the wrong size. I'd be awful if I had three wishes.

A lightsaber. Impractical against bullets, but it's the coolest item to have graced the planet.

I was beginning to think that I was the only person to want a lightsaber...
Karl

Tengen Toppa Gurren Lagann : A Mecha the size of a Galaxy ! :D

have fun destroying whole creation :) you will die lonely.
For me... simple
Gennie's lamp from Disney's Aladdin.

I want the magic ticket from Last Action Hero!