Not a massive fan of Giger but was sad to hear that he died earlier this year. Whether he's to my taste or not he was a talented and influential artist. He's probably best know for his input on the design of the film 'Alien', which is a little unfair.
I love NC Wyeth. His illustrations for the James Fenimore Cooper and Robert Louis Stevenson books just really strike a cord. Have to agree with MC Esher as well. Wish I was introduced to him back in the day if you know what I mean.