Two guys like me. Advice?

Two good friends of mine who I have know for years are both into me, and I don't know what to do. One of them (call him Gabe) asked me out two summers ago, and I said no. Since then, we've become really close just as friends, but according to other friends he's still into me. The other kid, who I'll call James, started liking me this past summer. He took me to prom in June when we were just friends, and starting liking me about a month later.

I honestly can't tell whether I like Gabe, James, or both of them back; it's confusing. I could see myself dating either of them, but I can't imagine choosing between them. I think that means I don't like either one of them enough, but I don't know. Gabe is the sweetest guy in the world, and I'm really comfortable talking to him about anything. But if I lost my friendship with him, I'd be so crushed. James I would have less trouble loosing as a friend because we don't talk as much, and he's a very cool guy, but I don't think I would be interested in him that way if I didn't know he was interested in me.

If only one of them liked me and then asked me out I think I would say yes to either of them. But since it's both, I don't feel comfortable doing that. I'm not dying to be in a relationship or anything, I'm perfectly happy being single. But I don't know what to do with them! One of them has to stop liking me, or something, because I can't spend even time with one without the other getting weird and I hate that.

Advice?