each one of mine has its own job and memories.
Squire Bronco - First bass, cant part with it ever, its purpose was to start me off, would probably gig it one day just for fun.
SX Jazz - After lusting for a Jazz bass i finally got one, after a few mods its beautiful, its purpose was as my main gigging bass.
Ibanez ATK405 - My 2nd 5'er, after hearing the sound of a 4 string ATK i had to get one. Used for most dropped D songs so i can play it in one position rather than drop tune, and thats its purpose.
Fender Aerodyne - To fill in my need for a P-bass. but with a twist, so far its excelled (Thanks Paul). Its my main bass at the moment, and when i get back into gigging itll take over the SX's duties.