Which one is best among D90 and D5200/D5100 Nikon SLR cameras?

Want to buy SLR Nikon camera. Can someone please advise which one is good among above models and also advise the good lense.

Okay, first of all they are all good cameras and any of them would give you excellent images.

The D90 has the weakest sensor and lowest image quality of the three, but it is the most weather resistant, heaviest and physically strongest of them. It also has an in-body focus motor, meaning that it will autofocus with older AF-D lenses. That motor may not matter if you don't already have lenses unless you are intending to buy secondhand lenses. The D90 is also better with flash, particularly for controlling multiple flash setups (which isn't going to be cheap!)

The D5100 outperforms the D90 in nearly about every other respect. The sensor is better, particularly in low light where noise is much reduced. The moveable screen is very useful.

The D5200 is a bit of an unknown. We know the specifications, but no reliable independent reviews have been seen yet. The 24MP sensor is not the same one as the D3200, so it's hard to compare. It's likely that image quality will be better than the D5100, but that comes with larger file sizes which mean you will need a faster PC with more RAM and disk storage to cope with it.

The D5100 is capable of 4928 x 3264 pixel pictures. That would give you a 24"x16" enlargement at 200 pixels per inch, which would be good quality. Just how big do you want to go?

The D5200 is likely to have improved video over the D5100, but that and the extra resolution come at quite a big price hike. Can you afford that extra and do you need the extra resolution?

The other option is the D7000, which combines all of the advantages of the D90 and the D5100 with the exception of not having the D5100's moving LCD screen or built in effects like HDR - and then adds quite a lot of advanced functionality.

If you can afford it - and don't mind the weight - the D7000 is a great camera and I'd highly recommend it. Review here: http://www.steves-digicams.com/camera-reviews/nikon/d7000-dslr/steves-conclusion-118.html

For lenses, the 18-105mm VR lens is quite a lot better than the standard 18-55mm VR kit lens, but if you can afford it the 16-85mm VR is better again and a lot more flexible if you do any wideangle work. The 18-200mm VR is a good all-rounder, but it is quite big and expensive. Having said that, as kit lenses go the 18-55mm VR is a good one and would get you off to a good start if you can't afford better.