OOh a question to stir up a hornets nest.
Well generally thought that Intel better for editing movies and the like
AMD for gamers
So a quandry for you to start with.
However I use Intel cpu's and I play games.
That said AMD are better (much) value for tthe money and the X2 chips seem to beat intel across the board in benchmarks.
XP or media centre.
Really down to your preference. Read the specs compare prices and decide.