Personally I build whatever catches my eye!
Used to be that if it didn't have at least four tires and eight cylinders(or at least a replica thereof) I wouldn't go near it...ok...maybe dabble a little in sci-fi...but you can't prove it in court!! (there's nothing wrong with sci-fi! So anybody who is a fan of it don't send me a bloody taarg's head! Klingon pet? Anyone, anyone?)
Point being, ever since I started going to the local IPMS meetings about three months ago, I've been turned on to a WHOLE new world of modelling.
Killer aircraft, cool armor, and a few ships too!
Then again, whats the point of any of it? Its just painted plastic!
Of course, I think that it keeps me from visiting the local water tower with a high powered rifle... :D
Carlos