when you have money to do it
Epiphone G-400!!!!!!!!

Washburn Bass!!!

Cordovox tube amp

Crate bass amp!!!

Kustom PA
Upgrade your amp first.
Barry White is cooler than you
Quote by Deliriumbassist
I really wish I could say you're funny and cool, but that would be like saying Africa doesn't have a poverty problem.
When the old one doesnt work. Really, it doesnt matter what kind of guitar you have, if your a good player. If you just cant stand certain things on it, like maybe you have single coils and want humbuckers, or vica versa. Personally, I just play epiphone les pauls, their beginner guitars, but whatever, they work just fine and have painted necks, which I love. But I could play any guitar and it wouldnt really matter to me, I prefer my Jackson Rhoads with 24 frets and a floyd rose, but I dont have to have that to play, I can just play my classical acoustic, and it doesnt matter too much. They only thing i'd sugest, maybe have a guitar with no limitations to you, such as 24 frets, locking tremelo, neck thru body construction. Really the thing that I find is a big factor is a neck thru body or set neck, I am not a fan of bolt ons, and I dont own any, but it doesnt matter too much, lots of people love them, aka fenders.
But dont ever for one second think a new guitar will make you better, the only thing is, somthing such as active pickups might make crappy legato sound a bit better, only because it picks up the note a bit better, but it picks up the slop too. I'd suggest pick a body style you love, and pick a setup you love.
if your'e a beginner and have a beginners guitar then you should upgrade as soon as you know for sure that you will stick it out and not give up. as quebecmetal suggests though, the amp is a more important upgrade. You can sound good with a rubbish guitar through a great amp, but rarely through a great guitar and a really rubbish amp!

You will find that you will get to a point where you will always want a new guitar. I have a great Les Paul copy which has been upgraded, and a fender strat, and yet i still bought an SG copy a few weeks back! why? GAS!