I was gonna say one prize that'd be really cool, but then I remember that I need to be a nicer person & not make really bad jokes
I think most poeople would like most prizes, but you're always gonna find things that people don't really need OR winning the prize causes unwanted problems - like hosting is a really cool prize in theory, but I wouldn't want to win it because I am very comfortable with Nat Net
A link list script would be a cool prize, unless you had no plans on starting a link list
A tour and banners & graphics would be cool, unless you had no pay site to use it on.
I could go on & on & shoot down pretty much every prize anyone could think of
But, I will say that any prize that's given away at someone elses expense is pretty much a nice thing to do & odds are, someone will be able to use it