Which camera is best for a beginner?

I want to step into the world of DSLR photography and learn photography. I'm a complete novice and have only had a Sony point and shoot camera. While I want to learn every aspect of DSLR photography but since I'm a beginner I don't want to spend too much. I have shortlisted Nikon D5100, Nikon D90 and Canon 600D. Although I prefer the image quality of Nikon entry level DSLR I'm still ready to go for Canon but in the future if my progress is good I would like to purchase Nikon full frame camera. Actually I'm leaning towards D5100 but I'm not sure if this camera has everything. I do not want to choose a camera that could hinder my learning graph. I wanted to go for Nikon D7000, but after hearing a lot of focus related problem I don't want to invest double the amount of the camera I've shortlisted on a camera with so many problems. Is D5100 capable of auto bracketing for HDR photography?

Panasonic