Well, I think here, both sides are partly in the right. As much as I'm sure you hate hearing this, you are still pretty young. You are still their responsibility, and it sounds like they take that seriously, and care about protecting you. The PG-13 movie restriction is a bit much, but they, for whatever reason, don't think you're ready. It sounds like they need to loosen up a bit. Have you tried talking to them? Like, seriously sitting down and asking them to lighten up a bit? I had a friend whose parents were like that. He got tired of it all, but he was afraid to confront them. Instead, he wrote them a letter, explaining how he felt restricted, and needed them to let him live a bit. And they listened, and they did back off, a lot. Of course, he ended up getting in with the wrong crowd, and was an alcoholic by the time we graduated. No clue how he's doing now, actually. So, it's a tricky situation. You clearly need more breathing room than what they're giving, but at the same time, are you ready for it? I don't know you, so I can't answer that. But be careful. The best thing to do is to talk to them, and show that you're ready. And yes, you did say that you get good grades and all that, but that doesn't seem to show them enough.
As for the specific issue of video games, first off, I do have to give kudos to the parents for actually paying attention to game ratings, or at least to what their kids play. That's a bit unusual in the world today. Good for them for caring. I know that's not what you want to hear, but these games are rated M for a reason. And I know you play them anyway, and don't see the problem. But someday, you'll probably be able to look back and understand why. I was a teenage gamer who didn't think much of violence in games, but now I do think it's good to have ratings and such. No matter what they think, kids and teens are often not as ready as they think. I'm not saying you're not ready, but you might not be as unaffected by it as you think.
Dunno if that was helpful or anything, but there it is.
EDIT: For over-protective parents, I'm surprised by the cell phone thing. You'd think they'd want you to have something that could act as an emergency aid.