As far as I am concerned, Nikon or Canon are what to get. I prefer Canon, but others I know prefer Nikon. I don't think you could go wrong with either brand. I wouldn't get anything outside of those brands though. I don't trust Sony cameras, or any other brand really.
I'll be as honest as possible, while trying to not sound bias.
I shoot a Sony Alpha A-100, but I prefer Canon
What do I think of the Sony?
Well, I was a little hesitant at first. I thought it was a dumb camera and my initial thought was, "Sony? Ehhh', They don't sound like they would make a good SLR camera..."
Then I found out about the whole Konica-Minolta and Sony combination and I began to think more towards the Sony camera. I had an older Minolta 9xi 35mm SLR at home, with a standard 24-85mm 3.5-5.6 lens, and I realized I could use the lens. This was a plus because I could potentially save some money in the future on lenses from Minolta that are used but in good condition. Minolta had some great glass back in the day. Finally, I realized that it was mostly a Minolta camera, with Sony's name on it.
I read about the features that Sony's camera had to offer. In the end, I realized that the pros kind-of topped the cons.
I was comparing this to a Canon XTI and a Nikon D40x by the way. Because those were my only other options at the time.
Canon had the "dust removal system", sony did too. Canon had the auto dim LCD when your eye goes up to the viewfinder, Sony did too, and sony also had Minolta's old Eye-Start AF system so that it will auto-focus when your eye hits the viewfinder sensor as well. Canon has a 9-point AF, Sony has a 9-point, whereas the Nikon has 3. One of the biggest advantages was the
effective Image Stabilizer built into the Sony body. So in the end, any lens you stick on the body will have an IS thanks to the body. Sony's LCD also rotated as the camera body went into portrait/landscape style. The alpha's evaluative metering system was also quite effective, even in some challenging scenes. Also, the batter life is great.
To be fair, here are the things I don't like.
You really can't push your ISO past 800. 400 is the safe zone. After that, you are risking some serious grain. To get to things like ISO, WB, metering mode, focus mode, and etc... You must use the "speed dial" at the top of the camera. It's not that bad, but it would've been nice to have dedicated buttons.
Overall, I'm happy with the camera. It's gone through many hours of portrait work, as well as day-to-day camera use. Will I get a Sony camera as my next upgrade? Maybe... But the real camera I want is a Canon 5D.
If I can say one thing in the end, it'd be to never judge a camera by its manufacturer. Well, at least not always. I was hesitant because it was Sony's first ever dSLR on the market, and it wasn't receiving many reviews. So when I compared the specifications, I realized that it was a pretty good camera, and it really is.
If you have any questions, feel free to ask.
Best,
-AC