I really didn't know what answers to expect, but I found myself thoroughly enjoying their responses, and thought you might, too...
Newton. Honestly, I feel that his work was more useful. Plus, he did much more that I know of other than calculus.
If I had to choose, I like Newton because of his wide range of scientific contributions. Also, to be honest, his name is easier to pronounce!
I like Newton better because he came up with the laws of motion and his name is easier to pronounce.
I like Newton better because he also came up with his physics laws.
I like Newton better because he has a lot more to do with science in my opinion and I like science a lot.
Leibniz all the way. Integral signs are fun to draw, and he's overshadowed by Newton too often.
Newton because he's more well known.
Leibniz notation, while more "foreign" is much more straightforward. Newton, though is considered to be one of the greatest minds in all of history (according to Neil deGrasse Tyson). I appreciate both their mathematic contributions equally.
I like Leibniz's notation better.
I like Leibniz better because he has a cooler name.
Leibniz because I like his notation better.
I like Newton better because I can spell and pronounce his name. :)
I like Leibniz better because technically he invented calculus earlier than Newton.
Leibniz. His notation was easier for me to understand.
Question for the blogosphere--whom do you like better, and why?