If I were you, and had to start all over again with a basic kit, I'd buy second-hand, regardless or which brand or model I go for. Assuming you buy from a reputable and trusted seller at the forums here at the B&S, and know what to look out for, you'll be pretty safe. Like all electronics, people are constantly moving and upgrading, which often means they're dumping their previous DSLRs at good prices.
If you're not confident dealing second hand, then consider looking for brand new ones, but go for models that are one generation old. In all likelihood, the features will still more than meet your needs but they'll be priced very nicely. Things like the Canon 350D, 20D, Nikon D50, D70 and D70s are all capable cameras. There's plenty of other brands you can consider as well.
Like most things there is no 'best' camera. There's only the 'best' camera for each individual user. Things are so subjective, so it would be wise to read widely before you buy. Nobody will be able to give you a full comparison between brands, and only you can decide for yourself, based on your own priorities. Get reviews from reputable sources, for example:
www.dpreview.com
www.dcresource.com
Read everything from start to finish, unless you're in a rush, in which case you may want to just stick to Photographic Tests and jump straight to the conclusion at DPReview. Buy carefully because when you buy an SLR, you're buying into an entire system. Ensure that the company makes the lenses that you forsee you may use, or at least see if the company produces an extensive range to suit all budgets.
I went straight for the Canon 350D based on the clean images throughout the whole ISO range (relative to other cameras), and the size of the camera. To me, silky smooth images are a priority. BUT, do note that one photography magazine I read said that the 350D's noise above ISO 800 was completely unacceptable, and they preferred the more film-grain type pattern in the Nikon D50. It shows how subjective things are. In fact, after working with a degree of noise in some of my images (while using ISO 800 film) my tolerance for it has increased over time, and to me, a noise/ grain doesn't necessarily destroy an image. And assuming you get everything else right [composition, subject, lighting, correct moment], noise is hardly an issue to think about.
END RANT HERE :bsmilie: