Oh wow what a question! I’ll try and narrow it down a little but for portraits and travel I’d have to go Steve McCurry, for street and ‘absurdism’ Elliott Erwitt and someone who I have somehow only just discovered — Spencer Tunick, incredible work.
A few more;
Ansel Adams — his Yosemite photos are some of my favourite Landscape works
Diane Arbus — her portraits makes me feel very uneasy and that’s why I love them!
Sean Tucker — Love his portrait work but it’s his street work that really gets me. Very active on Youtube too and a real breath of fresh air