Canon 350D or Nikon D50
Stay away from Olympus.
If you're after a real bargain, have a look at the Pentax *ist-DS
In general, stick to Canon and Nikon because they have a huge range of lenses available at good prices, whereas the less used brands either cost a lot more or there isn't enough of a range available.
It's too hard to just give a price range and say what camera is good.
Look through dpreview.com and choose 2 or 3, then I'm sure there are a few people that can give you the ups and downs of those particular cameras.