On his Discerning Photographer blog, he recommends picking and sticking to one manufacturer:
Buying a camera is the beginning of a long-term commitment. You’ll most likely end up buying additional lenses, strobes, and other accessories for this camera, all by the same manufacturer. Eventually you’ll need another, better camera as well. You’ll want your lenses to fit on the new body. And on and on ... so choose carefully, and plan on staying committed to the choice you make.OK, so which DSLR brand does he recommend? Canon or Nikon.
Dollar for dollar, day after day, year after year, these are the two camera manufacturers who have consistently led the technological charge and delivered high quality, innovative yet very sturdy, dependable products for the advanced amateur and professional photographer. There are other excellent cameras on the market, and you can buy into another system if you choose. But I will tell you unequivocally that Canon and Nikon are the two safest bets you can make.Which is better? Well, for that you'll have to read his blog, where he makes some side-by-side comparisons of specific models -- including the (under $1000) Nikon D5000 vs. Canon T1i, and the (over $1000) Nikon D90 vs. Canon 50D.
A lot depends on your specific needs and preferences, and ultimately you should go to a shop and try them out for yourself, but Boyd gives you some important criteria to think about. Plus, as it's often been pointed out, quality photojournalism (and videojournalism) has more to do with what's behind your eyes than what you're holding in front of them.
(Image copyright 2009, Andrew Boyd)