Bass all the way for me. As a 12 - 13 year old I was massively influenced by Geddy Lee, Chris Squire, Derek Forbes & Adam Clayton & just wanted to play bass. Saved up my paper round money to buy my first one - a no brand plywood piece of sh*te. I didn't care at the time - I was just so pleased I had a bass.
Over the many (many!) years that have passed since then, I have dabbled with electric & acoustic 6 string guitars but they just don't give me the same buzz that listening to & playing a bass does.
From as long ago as I can remember, when I listen to music, my brain & ears have always been focused on the low end.
The fantastic gear that can be bought these days for a very reasonable money (both new & used) just blows my mind & adds to my bass playing experience.
So does all the options of 5, 6 (or more!) stringers, fretless, slap playing, active or passive, double bass etc etc...
It's a very interesting topic & question. I think though I would start one with "Why the hell would you [i]want[/i] to play guitar when you could play bass?" !!