I would have to go with the Acoustic Guitar.
The Electric Guitar is indeed a remarkable guitar, it relies on other instruments for it to unlock it's full potential. While it may not seem like it to some people, some songs sound very nice in an acoustic version.
people like one of my dorm-mates collectively ruined the acoustic guitar for me.
you know, he's the guy at the party who knows 3 chords and pretends to be sensitive and stuff.
So i'll go with the bass guitar. I've been listening to a lot of rush lately.