Need and Appreciate Your Advice: Should I Stay or Should I Go?

First off I just want to thank everyone who reads this in advance, I appreciate your taking time to help me out on this issue. Let me tell you about my dilemma...
My girlfriend and I have been dating for 8 months now, and she is 22 and I am 19 and both of us are in (different) colleges. She is beautiful, sized in all the right areas, and looks like a "porn star" to quote friends of mine. In addition to this she's also one of the nicest people I have ever met. I've loved dating her, when we're together we almost always have a great time. However what with our academic situation, we haven't been able to see each other as much as we'd (mostly she though) like to and as a result we've gotten in some fights recently about that. She insisted that I put her second to my friends and didn't care about her enough anymore, culminating in a huge fight that left me thinking we were going to break up. We reconciled, of course, as we always seem to do, but we do fight a lot. We aren't exactly similar people; things from music (country-rap) to religious values (religious-atheist...I've gone to her church with her for her). She also has a rocky past, she had been cheated on by some of her boyfriends and as a result until recently (when we had a fight about it) she would often insinuate that I was going to cheat on her, or make comments of that nature. In addition to this she also isn't my intellectual equal and she doesn't like talking about the same things I do (philosophy, politics, etc) however recently she has made an attempt to change (she now watches the news). She also seems to be very dependent upon me, whenever something goes wrong she calls me expecting me to be able to fix it and she used to call me like four or five times a day for long conversations and getting pissed when it couldn't happen (although to her credit she has stopped calling me as much and when realizing I am with my friends she says we can talk later). She's head-over-heels in love with me, loves me a ridiculous amount which I'm grateful for, but I think her level of commitment might be higher than mine. I mean, she's a fantastic girl, she's everything I thought I wanted, but I just don't know. All my friends say I complain about her a ton and she gives me a ton of stress and recently I've been (I think I've convinced myself to) thinking of breaking up, and this isn't a new thought or idea I've had it a good amount of times before. But she makes me happy when I'm with her and she IS changing for me, I just don't know if it's enough, if I should stay, go, give her another chance (but is that not unfair to her if I don't think it's viable-long term)?
PS. Anything else...ummm I've attempted to cheat on her in the past but never actually done it (and yes, I know, before I get 1,000 replies on the matter I know "cheating is bad"). I don't really know if I can see it as a surefire long-term thing anymore (I used to...), which is what she does.

Thanks guys!

Well look at it this way, the guys cheated for a reason......even tho she may look good on the outside, she doesn't have enough subtance, or independence to be interesting enough for a long term relationship. Compatability is very importatnt to hold interest once you are past the infactuation stage. Take a step back, and see her without her looks....now what is truly left over....just a nice person, that is needy, demanding and depends on you to entertain her. If you find your self wanting to cheat, that is a sign it's time to move on because you are just not that into her.....that she really doesn't do it for you.

Hopefully she will grow up a bit more and stop depending on her looks so much to get what she wants and that there is more to life than having a BF to do everything for her.

totally agree with smackie9.
If you get to the point that you need to find something outside the relationship......that means it's probably best you just end it.
It's better to leave her before she gets even more attatched and you cheat.... which will just hurt her more in the long run.
And it's better for you to find someone that you feel a deeper connection with and doesn't keep you looking for more.

I have to say something for this one.... firstly, YOU CAN NOT AND SHOULD NEVER EXPECT SOMEONE TO CHANGE TO SUITE YOU. Number one.. big mistake. How would you like it iF someone kept asking for YOU to change, like you're not good enough for them?? It's no wonder the poor girl feels insecure with you!! You think you are too cool for school and she's not good enough for you! So leave her now. Let her go, for her own good, and for yours. You will only end up looking like a complete and utter jerk (if you haven't already).. if you keep her hanging on to you. She deserves better, don't you think??? Does she have a heart?? Thats all you need to know!! If you know you need "better" or whatever, then go and get that!