Tell Us Your Favorite Scientists

From a reader named Thomas Kennedy comes the following e-mail:

I am an economics teacher from Alaska. I can personally list my top 10 favorite actors, top 10 favorite living writers, top 10 favorite rock groups, and even my top 10 living economists and top 10 entrepreneurs; but how many out there can name their top 10 living scientists and top 10 living mathematicians?
I wonder what your readership would say.
I have asked my students this question and they look at me in terror. They get to Stephen Hawking and that is it. This is a group of extremely bright A.P. Econ./ A.P. Chem. geeks.

Thomas goes on to bemoan his belief that “within our society, we are more concerned with money and big living … than we are with our scientists and mathematicians.”
I understand where Thomas is coming from, but really: are we to think that kids 20 and 50 and 100 years ago really sat around making up lists of their favorite mathematicians and scientists?
People love lists for lots of reasons. Personally, I like to-do lists because they’re useful, but I hate making “favorite” lists, and in fact couldn’t tell you who my “favorite” writer or musician or ballplayer is, or even my top five. So I guess I’m not a good candidate for Thomas’s exercise.
But maybe you are.
So let’s hear your 10 favorite living scientists, as Thomas requested. Maybe we’ll get to mathematicians another day. And after that, economists. Remember: not necessarily 10 best, but 10 favorite.
If you’re up for it, tell us why you like each of your favorites; a word or three will do. It will also be interesting to see who qualifies as a “scientist” these days.
For some inspiration, you might want to read Nicky Dawidoff‘s very entertaining profile of Freeman Dyson. There are a couple of good Richard Feynman stories in it. If Feynman weren’t dead, I am guessing he would appear on about 90 percent of your lists.