Ok, for one. keep your windows xp cd. download BootCamp from apple(if your getting a new one, it should already come with it)
with that you can use windows nativly AND mac. beautiful huh
next is, if your a gamer, dont switch...mac = bad gaming, UNLESS you get the mac pro and then boot camp.
mac is pretty basic. runs under the safe and stable "unix."
hmmm
if ur a real hardcore computer user who likes to spend his time learning a poopload of code, go to linux.
I dont think its worth it, simply becuase i dont have time. but linux is very good and fast.
tip: anything is better then windows