being right-handed, using WASD is easier so i can use the mouse if needed and its useful being there with access to all the other keys on that side of the keyboard
I prefer WASD, I am left handed BUT i've always had to use my right for the mouse sense everyone else is right handed not to mention I used to play first person shooters ALL the time.
WASD because it's so much easier to reach the other buttons. I only use the arrow keys if we are going to share the keyboard with a friend (like Mortal Kombat, Street Fighter etc.)
Besides I play Warcraft so I'm used to my hand being there.
Well, it really depends on the other controls. If I need the number pad, I'll go WASD. But if I need Capslock, shift, or ctrl, I'll go arrow. Either way, I can play a game regardless of the keys. xD
Arrow keys are easier for the right-handed people. And I'm right-handed. So, It's Arrow keys, but WASD is also ok, sometimes I might use them, if you can't use the Arrow keys ^^ Maybe more of the left-handed people use WASD... I dunno.
WSAD beacause if you use WSAD whit the left hand you can reach easily ctrl alt and space q, e, r and so on. and vor the most games i play you need those