Charles Darwin is ok I guess... :)
I prefer Alfred Russel Wallace though. He was more of a boots on the ground naturalist and not as obsessed with barnacles as Darwin. He also (possibly) came up with natural selection before Darwin, which spurred Darwin into publishing Origin, so even if he wasn't first, he certainly played a part.
It's this quote, from his book The Malay Archipelago that really made me like him though:
"The beauty and brilliancy of this insect are indescribable, and none but a naturalist can understand the intense excitement I experienced when I at length captured it. On taking it out of my net and opening the glorious wings, my heart began to beat violently, the blood rushed to my head, and I felt much more like fainting than I have done when in apprehension of immediate death. I had a headache the rest of the day, so great was the excitement produced by what will appear to most people a very inadequate cause."
That butterfly (species) now bears his name, Wallace's Golden Birdwing.