What is the best camera and type of lens to buy for taking photos of wildlife and landscapes?

Landscapes generally require a wide angle lens, and wildlife generally requires a telephoto, so you will want two lenses.

Pick any dSLR that is current or up to two generations old. They will all perform well, the older ones may lack some nice features but these features are not critical, they are just nice to have - if you use them.

For lenses, Nikon is the best for Nikon lenses, but Sigma, Tamron and Tokina all make nice lenses. Get the pro level lens in each line. VR/IS/OS... is nice, but not a requirement. For wildlife, get something that goes out to 300 mm at f/4.0 at least (a 200mm f/2.8 with a 1.4x works as well). For landscapes, get a fairly wide zoom, 10-12mm on the wide end, that opens to f/2.8 or f/4.

In the high stakes battle, it's Canon 1D X vs Nikon D4. I'd say the Canon has the more sophisticated AF system and the more interesting lens selection, but the Nikon has the edge (marginally) on build quality and sensor performance.

With lenses, a selection of 200-400mm zooms, and 600mm f/4 prime plus a doubler would be useful, to give you reach. These lenses demand a stable platform so a serious monopod or tripod would be essential.

If you're on a tighter budget then, Canon's 1D mkIIn with the 400mm f5.6L is probably the standout product pairing in this class. You'll still be looking at spending £1000 though.

Additionally hides, and clothing and lures are all useful additions.

Forgot to cover the landscapes bit...so to add. The best camera for landscapes would probably be the Nikon D800 or 5D mkIII, they're both smaller in form factor and still weathersealed. You'll want a weathersealed 16-35mm or 17-40mm type lens to do with it and weathersealed 70-200mm or 135mm prime. And a solid tripod. You could also consider packing a Plaubel Makina 67 or Mamiya 7 or if you're brave a Mamiya RB67 or Fujifilm GX680.

I am on a budget so I got a Nikon D3000 when Argos briefly had it on offer. Then I read an article by an American photographer about what equipment does she always take with her - her answer was a Canon 18-200 mm lens because it could cope with both wildlife and landscape so she wouldn't have to change it. So i bought the Nikon equivalent and even though it was secondhand it was still more than the actual camera itself.

As others have said, landscapes may require a wide angle, depending on the desired perspective, while wildlife will tend to require a "telephoto".

A single zoom covering the whole range, will be a compromise compared to seperate zooms covering a smaller spread each, which will tend to have better quality or wider aperture.

For wildlife, you may also need a decent maximum aperture, to keep the shutter speed high to freeze action, and to allow acceptable handheld results with a longer lens.

For landscapes, a sturdy tripod would allow long exposures, with the lens stopped down for depth of field - though for wildlife, a lighter monopod may be useful to brace against.

NB. You do not want an expensive camera on top of a flimsy tripod! - even with a sturdy one, you really want a cable/remote release to avoid jarring, though a compromise is to use the camera's self timer, so your hand is off when it takes the longer exposure.

The best camera and lens combo for wildlife is totally different to the best combo for landscapes.

The best for landscapes is a medium or large format camera with wider lens.

the best for wildlife is an SLR or Dslr with a long lens for birds and medium to large wild animals or a good macro setup for smaller insects etc.

sony Alpha 100 with low cost 70-300 mm sony lens or Sigma is best I used for

i have a lumix panasonic g10 i was dieing for a dslr for ages, i have one but its pretty terrible, it does a wide range of things but for close ups and landscapes its terrible, it doesnt blur the background out verry well and weather its because i have a fisheye lense and the lense it came with, or if i need better lenses for it im not sure, but theyre all just so expensive yano!?

anyway i got it second hand for £200 so i cant really complain

its my only camera and its terrible and i know im not answering your question but the advert for it lies and its aweful at distant landscaped so stay away from lumix panasonic dmc-g10s!