Your question is a little like "Which shirt is the best to go with these jeans" It's a bit subjective. Apart fron the advice given by Marcus above, it'll depend what you like personally. With a shirt it'll be colour, pattern, length of sleeve, etc, with Linux it'll be... Well, only you know.
However... as in buying a shirt where you go round the various shops and look at what they have, with Linux you go and download LiveCDs which boot and run Linux in memory so you can see what you're getting before you install.
You should perhaps check the forum (Try the Search function) as this question has been asked numerous times.
Part of the fun is finding the Distro which suits you!
With Windows you get... er... Windows