I like Wamp's user interface a little better...
But, I don't think it matters much between them.

what i like about xampp is that instead of localhost i see example.com... actually that is the way i had to set it up when i was trying to learn zencart... unless you can do that with wampp but the problem i had with xampp was something with curl... it said if i am correct truning it on or something like that...
@arlin if you remember my other post about drop down menus i got it to work the way i wanted to..

There is now something called DAMP you might want to try. WAMP has a simple UI. xampp has more but isn't as simple. They both work.