let's just say there is no best of the best brand that all the pros use... end of the day it's up to personal preference, but all i can say is it seems like Canon and Nikon are the top 2 choices (at least for me)
This query has been asked more often than any other question and no one can answer this better than yourself. You'd need to be comfortable with the user interface (U.I.) as well as the whole system's accessroies.
Remember the old adage, you're not just buying a camera, it's a whole system to consider. READ MORE first... then go down to the shops and try them out. Dun get brain-washed along the way though, the salesmen will try to push whatever they have on hand or which they think will give them the best profits.
Make sure to try all the DSLR cameras in your budget from Nikon, Canon, Sony, Olympus and Pentax. And also consider if you really need a DSLR; remember, there's a LOT more tobuy than just the camera.
As I have mentioned many times in this forum. All entry level DSLRs, regardless of brands are able to give you decent pictures if you used them within their limits.
I would suggest that you shortlist the cams within your budget and try them out in a shop to see which suits you better, has a better user interface to you and is more comfortable in your hands.