I need a suggestion for a good Digital SLR, any knowledgeable photography enthusiasts with suggestions?

I am a photography minor and am finally ready to buy myself an slr, I have $600 to spend, but could go to $700 (I'm a waitress and a student, ugh). I would like something versatile with good focal length. I like to take portraits as well as landscapes. I'm used to working with a Canon Rebel XT eos but have heard there are similarly priced cameras out there with more to offer. Please let me know if you have any advice, my head is swimming with all the information :)