Really simple answer - other than getting into much more advanced photography, where you really begin to push the boundaries of low light capabilities, focus speed, buffer size, continuous frame rates, etc - which probably 85% of all DSLR owners do not, then even the most entry-level DSLR will give you an excellent tool, capable of excellent photos, and a brilliant teaching platform with flexibility to shoot any type of photography. It's what makes a DSLR system stand out from a P&S camera.
So brand, model, even an older one from a few years ago, as long as it's not broken, will be a fine choice to get you started in photography and can work for years in pushing you to be a better photographer. And as you feel the desire to invest in the system, buy good lenses - the best lenses can be kept and carried over to newer, better camera bodies down the road, and still be fabulous, so you don't really lose anything on the investment.
UKcatfan had some good recommendations - look at all brands, and handle them all too if you can - the Nikon D3000 & 3100, the Canon T2 or if they're still around T1, the Sony A390, 33, and if you can still find them around A500 & 550, the Pentax KR, and if you can still find them around KX. All good DSLRs as starteer systems, some with little feature content perks, or slightly better sensors, and varying sizes and grip designs, that might make one of them just right for you.
