To start things off this is a list of all the great value DSLR's that are currently available on MPB photographic starting from £59.00 ranging in excess of£2,000.
These are all of the Nikon DSLR's that are available, some of them are good deals, others are relatively poor, though this does give you an overview of what is available.
Nikon D100, £59.00, APS-C, By no means the best camera around though still capable, and for a fully working Nikon DSLR you can't go wrong, 6.1MP
Nikon D40, £74.00, APS-C, Good small budget camera, 6.1MP
Nikon D50, £74.00, APS-C, I would avoid this camera, not the best, 6.1MP
Nikon D80, £109.00, APS-C, Good but not great, worth the extra to upgrade to the D90, 10.2MP
Nikon D5000, £124.00, APS-C, Small compact with a flip screen, 12.3MP
Nikon D90, £159.00, APS-C, First DSLR ever to have HD video though and surprisingly good low light performance but shooting raw is a must with this as the files it produces i found were quite flat, 12.3MP
Nikon D300, £159.00, APS-C, 6fps 51 point auto-focusing system, similar to that in the D4, and great ergonomics making it a camera you will never want to let go of, though the low light performance is poor, 12.3MP
Nikon D3300, £184.00, APS-C, Good for virtually everything accept for sports, 24.2MP
Nikon D7000, £259.00, APS-C, Good all rounder 39 point focusing system, not the best focusing system, 16.2MP
Nikon D300s, £319.00, APS-C, 7fps 51 point focusing system, very similar to the D300 but has video and slightly better low light performance, 12.3MP
Nikon D5500, £424.00, APS-C, Not worth the money for the flip screen and WIFI over the D3300, 24.2MP
Nikon D7100, £479.00, APS-C, A great camera that really is all anyone needs, 6fps, 51 point focusing system, 1080p 60fps video, but the catch with this is the buffer that makes it very difficult to use for sports, 24.2MP
Nikon D3, £549.00, Full Frame, Great value for a camera that will never be recreated due to the expensive manufacturing process, great low light performance, 51 point focusing system, 9fps, this is definitely the best value camera here, 12.1MP
Nikon D700, £569.00, Full Frame, Produces the best files straight out of camera and is a great camera for portraiture, though the buffer is lacking for sports, 12.1MP
Nikon D600, £634.00, Full Frame, Good but the focusing system is something is out of a nightmare, a 39 point system that doesn't fill the prism. 24.2MP
Nikon D3s, £849.00, Full Frame, my personal favourite, as i own one, and i can say that it is worth every penny, great low light, up to 11fps, 51 point focusing system
Nikon D610, £859.00, Full Frame, Much the same as the D600, but without the oil sensor problem that will not hinder these cameras as they have done over 10,000 shutter releases, 24.2MP
Nikon D800, £1,149.00, Full Frame, Great landscape camera, but be careful that your PC will be able to process those massive raw files, 36.3MP
Nikon D750, £1,189.00, Full Frame, a Swiss army knife, can do everything but is not exceptional in one area is very good in every area, 24.2MP
Nikon D3x, £1,649.00, Full Frame, Not worth the money, just get the D750 or the D600, 24.2MP
Nikon D810, £1,799.00, Full Frame, Same as the D800 just with the low pass and anti aliasing filter removed, 36.3MP
Nikon D4, £2,079.00, Full Frame, the Camera that I dream of, if you are looking to buy this it needs no introduction, 16.2MP
Nikon D4s, £3,099.00, Full Frame, Same as the D4, but even more
Now these are by no means facts it is just my opinion, but it is based on research and having used a lot of Nikon DSLR's in my time. If i was to buy one of these at these prices it would have to be the D3, as it is the best value, but my wallet does not allow this at the moment. Hope this helps someone out coming up to Christmas.
All of these prices you will have to add £4.95 to for postage.