Like was already said, there are a lot of options. The one I went with recently was the Bestop HD tire carrier. It doesn't mount to the bumper, but rather uses the tub and roll bar for support.
Unfortunately, so far I'm not very impressed with it, despite the generally positive reviews I've read on here. Not all that easy to install, drilling into your tailgate and tub, and it uses those crappy jack nuts in two places (wtf... those things are worthless). Now that it's installed, it rattles going over bumps. When you close the tailgate, the whole wheel flops around and just looks generally insecure.
Sad to say because normally I like Bestop, but I'm pretty disappointed in it. I will probably be replacing it with a bumper mounted, swing out tire carrier eventually.
Oh... and it's only holding a 33x12.5x15, which it supposedly is "perfect" for.
Overall, I personally can't recommend it.