Capturing Pin Sharp( or Tack Sharp as pro photographers call it) image is the primary requisite for photography and has great impact on pictures you take.
with todays technology, it has become a lot easier to take steady pictures and there are many techniqes and accessories which are used in photography.few of them are here.....

The first thing to keep your camera still and stready and to take tack sharp photos is to use a "TRIPOD".The first thing that seperates pro photographers from the amateurs is that they use Trypod even when they are shooting in daylight because it really works. Tripod is only used to keep the camera still and steady.So u dont have to hold the camera anymore. but when it comes to Tripod, some tripods are good and some are just fine. Soo.. look at your pocket and the importance of pictures you are going to take.... buy a good tripod.

Since its difficult to move your camera fixed in a tripod so one gets fedup and juzz pull the camera out of tripod. So there is another thing which can help you move you camera without moving the tripod..."BALLHEAD".Ballheads are wonderful because with just one knob they let you quickly and easily aim and position your camera accurately at any angle

When you use a tripod... you get pictures much sharper but not tack sharp because when you press the shutter button on the camera, the pressure makes the camera shake a little so you dont get the tack sharp photos... here is the solution you can use a "CABLE RELEASE". A Cable Release is a cable which can attach to most of the cameras and it has a button on its one end. when you press the button on cable release the camera take the photo and you get a tack sharp photo.
However, there is another option in the camera which is somehow an alternative to cable release. It is the Self Timer. you can use self timer and the camera takees the picture without you touching it.

A mirror lockup is feature in your camera which can be reduce movement. when your camera is mirror locked, the mirror of the camera is locked in the up position so gives a sharper image.most of todays dSLR cameras has that feature.

A Good lense can make a lot of difference.go for a high quality glass and it reduces vibration.

When you increase the ISO, it add noise to you image so it is highly recommended to reduce ISO while shooting on a tripod.

Two other tips:

- if you use a tripod and your camera his some kind of stabilisation feature build in, then you should disable it.
- set the lens at the aperture that produces the sharpest result

Sonys have good build quality
Nikons I really like, very good cameras

Yeah, but I've read that thei alpha dSLRs have noisy sensors .

Btw, I'm not voting because there is no 'best' brand, every brand has sucky camera's in their line-up and the perfect camera doesn't exist. Ow, and you've forgotten a lot of brands like Fuji, Pentax, Hasselblad, ...

at college we have a Nikon dSLR and it works so well, its a REALLy good camera, I dunno how u mean noisey sensor tho :S