I really like Steve McCurry, some of his shots are a little posed for my liking quite often but they are technically superb with a very distinctive look and the subjects are without fail very interesting.
Robert Capa was another interesting one
Mark Laita takes the prize for simplicity, colourful animals on black backgrounds and not to mention his series of mexican wrestlers which is pretty funny.
Leigh Ortenburger I very much like as well. I saw some of his shots in a climbing magazine that really captivated me. He did mainly landscape photography, preferably high up in the mountains and he’d lug his 4×5 camera and tripod up to many thousands of metres up. His shots are all black and white, often taken in the middle of the day which makes it even more astonishing. If you happen to see an Alpinist 31 have a flick through it.