When checking for price/performance, the Sony Alphas are pretty nice. The major value is in the alpha mount. Sony bought Miniolta tehcnology and is rolling with that. You can pick up lenses made for the auto focus Minolta Maxxum line from 1985 until present. this definitely opens up opportunity to try different lenses and get to some quality items very quickly. The alphas have in-body Auto Focus and Image Stabilization which help control lens costs. If you can get to the 300/350, or above, they add live view which can be of value in composing shots.
As far as those one-off values, check Best Buy for dispalys. A local BB had a D40 kit display for $350 and a Sony A350 for $400. Personally, I picked up a clearance A300 from Best Buy for $400. I then found an A200 kit display for $180 from a Sony Style store. You CAN NOT beat that one! Be sure to check Costco or Sam's for their deal. They had a killer deal on the Xsi and maybe a D60 with two lenses for a very reasonable price. Sears also has some clearance and open box cameras at some stores.
At this level, I don't see that there are a ton of differences in features and quality. There are pros and cons of each, but be sure to hold the camera (I didn't like the canon at all) to see how it feels. Also, stick with a brand so you don't lose out on your lens investments.
EH