I like the previous answers, but I'll throw in a real one.

Nicest Bike:
1983 Bianchi Alloro - Nothing, it was a gift/pledge for riding an MS150... alternative was a borrowed Bianchi Mountain Bike.

Fun Bike:
Fuji Roadie converted Fixie - ~$80 bike, and somewhere between $200 and $300 once done.

BMX:
Used Cycle Craft Frame, Full DK build/parts - $200 if I remember correctly... that was back in 1994. Still ride it semi-regularly, so I think I'm getting my money's worth.