Which DSLR Camera Is Best?

Nikon

A professional would make his own choice, and you have two problems. 1) You left out Pentax - making SLRs before any of them, capable of metering with manual-focus lenses, and even their cheapest models have pentaprisms (if you don't know what that means, you can't call yourself a photographer). 2) Beyond the way they feel in your hands (and Sony's edge in video by NOT being true DSLRs) - there IS no, 'Best.' Normally, I'd suggest finding a dealer, looking at ALL the alternatives and making your own choice, but you aren't ready for that.

The Canon EOS-1D C is tempting. The new Nikon D4S is coming out unless you like the Nikon D3X. Sony α99 or Olympus OMD EM-1 or Pentax K3 seem interesting.

Your question ask's for one best camera and your text ask's for two(beginner & pro) best cameras. Sorry to be to the point but you don't want to do any homework or actual testing. For instance which camera or cameras fit your available price range? Which camera has features you like: Camera body stabilization rather than stabilization "in" each lens purchased?= Pentax! ...Which camera is physically smaller and easier to hold?=Pentax. Which camera enables you to save money on used lenses dating back to the film (cameras) using days?=Pentax. Which cameras have you not considered because they don't get the publicity on Yahoo Answer like other brands/=Pentax.. What brand camera will you be sorry that you didn't make the effort to check out as it applies to You=Pentax. I left a life-long love affair with Canon, because of the above questions and 3 years later have no regrets! Good luck in your "satisfaction" department.

They are all good cameras. I personally prefer Canon but Nikon, Pentax, Sony are also good.

Nikon D4 is best camera for the professionals Canon 7D- for Semi professional photographers

Nikon, Canon, Sony, Pentax.

If there was a 'best', wouldn't the others go out of business the next day? All the large manufacturers are excellent at what they do. We should respect that and learn about which one suits your needs. But first you have to figure out what your needs are. By the time you do that, you will know quite a bit. There's no short cut.

No company is better than the other, though a professional would choose nikon or canon due to the much larger lens selection than sony or any other company and also largely due to the addition of an optical viewfinder as opposed to an electronic viewfinder which are fucking disgraceful contraptions. A beginner in my honest opinion should get a film camera such as a Nikon FM2 which is entirely manual and you learn photography trial and error, you could pick one up for about £100 and a super sharp 35mm f2.8 prime lens for as little as £40. Serious proffesionals who are in a studio environment would opt for a medium format camera such as a Hasselblad or Phase One though I was never sure if they were actually DSLR's....