I want to say lightsaber, but without Jedi training I'd likely cut one of my own limbs off trying to use it. I'll go with Iron Man's armor, as it has so many uses. Would you rather see Data and C-3PO in a wacky, "Odd Couple" style sitcom, Worf and Chewbacca in a WWE type wrestling show or Odo and Boba Fett in a "Cops" style reality show where they hunt down criminals?
Data and C-3P0. Wrestling would get boring very fast, and Boba Fett doesn't speak much so it wouldn't be that interesting. Would you rather see Trip in a detective story or Picard in a Western?
I've actually seen Picard in a Western, and it was epic. So my vote's with Old Baldy, although watching Trip get nut-punched by Professor Moriarty would definitely carry some entertainment value. Would you rather have a Gorn or a Klingon as ship's counselor?
Klingon. People would keep their whiny crap to themselves! Don't know enough about Gorn culture to say how they deal with people--aside from killing them, that is. Would you rather have Leonardo da Vinci or Moriarty as your Holodeck pal?
da Vinci. When he gets annoying, he can be turned off. When Moriarty gets annoying, he takes over the ship. Would you rather discover that your blind date is a Tholian or a Breen?
A Breen. I assume they're hairy but I'd rather be a furry than someone into insects. Would you rather give Spock, Worf, Kira, B'elanna, or Phlox a back massage?
A Time Lord. They generally don't screw with people just for the fun of it. I might even get a TARDIS ride out of it. Speaking of Time Lords, which of the eleven (soon to be twelve) Doctors would you rather see join a Star Trek crew, and which crew would you want him to join?
^13, actually. Doctor #4, Tom Baker, on TNG, would have been a thing of beauty. Doctor #9, Christopher Eccleston, would have fit in nicely with DS9, I think. Would you rather see a sit-com starring the TOS crew, the TNG crew or the ENT crew?
TOS crew. Kirk, Bones, and Spock would make the show a definite win. Would you rather have Bones, Ro, Bashir, Paris, or Trip as your roommate?
Bashir or Trip. Either one would make me very happy. VERY happy. Would you rather have Kirk, Riker, O'Brien, or Reed as your uncle?
O'Brien, he seems the only one who would want to have fun with you in ways that aren't kind of creepy. If you lived in 24th century Earth, would you apply to Starfleet?
Yeah, probably as an engineer. Would you rather invent the next big recipe, holonovel, or play? (any timeline)
Holonovel. It's like designing a video game, writing a novel and making a movie all at once. Would you rather be a sentient android, a sentient hologram or a sentient starship like Tin Man?
Android. It'll be easier to repair myself if anything goes wrong. Would you rather see then Enterprise 1701 in the Star Wars or BSG universe?
BSG: the style of combat, on both sides, would make 1701 an interesting counterpoint. Would you rather have an EMH based on Dysek or an EMH based Antaak help you with a critical injury for which you cannot pay?
Since Dysek's species DON'T treat people who can't pay, I'd have to say Antaak. Would you rather serve on a regular-universe Klingon vessel, or a MU Terran Empire one?
A Klingon vessel. I'd be the Worf of the Klingon Empire. Would you rather owe Quark, Nog, Rom, Brunt, or Grand Nagus Zek a favor.
Nog. He's the least annoying and most honorable of the bunch. Rom, while nice, would probably ask you to do something for Quark, which would probably NOT be pleasant. Would you rather have to work side by side with Q, Weyoun or Seska?
Weyoun. Jeffrey Combs wins every time. Would you rather have to unexpectedly host a Trill symbiont like Riker did, or be on the receiving end of an unwilling Vulcan mind meld?