NIKON!
I use the NIKON D80 and D300 and have a variety of little gizmos to go along, I swear by the Nikon product and have never had any problems to write home about. They have great customer service and a very nice aftermarket following with many quality companies that make any lens, filter or accessories that you would need.
I would save up a bit more and go for the D3100 (like some others have said). When you go with a DSLR you want to get something that is a quality product - Just remember that your camera is only as good as the equipment you put on it. Make sure that when are selecting things like UV filters, Polarizers and Lenses you get quality because a cheap lens on a good camera negates the fact that you got a good camera in the first place.
Happy Shopping!