I have tried the guitar and hated it. I quite like the banjo and wouldnt mind having a go at learning it. Is it easy to learn. Is it similar to the guitar. I love blue grass music but have never tried to play a banjo. If you are a guitarist is it easy to pick up the banjo. Spmeone said it is better if I can first play the guitar as they are both similar instruments.
Start with the guitar. They are both very similar, so if you had trouble with learning guitar you'll most likely have trouble with the banjo. Also the guitar is a much more versatile instrument. I love the banjo but the guitar is in my opinion the greatest instrument of all time. Get the hang of basic guitar (chords, picking, scales) then move on to the banjo if you still aren't motivated with the guitar.
if you like picking with your fingers the banjo or classical guitar is something to look at. I start out playing the aucustic guitar but after a couple of weeks knew, na this wasn't working. I moved to learning the classical guitar for the simple reason that its easier on the fingers... don't quit!
Take a go at a classical guitar if ya can, and see what that's like. If you like that the banjo would be great for ya. Good luck