when i went to go choose between xbox 360 and ps3 these were the points that came to mind
pros - generally built for entertainment (movies, games) has built in wireless ethernet adapter, can play blue ray dvds, online access free, more hard drive space to save movies and such
cons - systems are generally more expensive, systems arent streamlined certain systems can play certain games (ps1 and ps2 games), certain systems cant. The systems that can play the old ps1 and ps2 games are discontinued theyre supposed to be reissued but theyll cost you roughly 500-600. If you do happen to get the system that allows usage of old PS games the games you can play are severly limited. If you want to play the old ps games you would have to buy a ps2.
pros - built for games, majority of games from xbox are playable, system is generally cheaper
cons - no wireless ethernet adapter, does not play blue ray, small harddrive (not built for movies), you have to pay for online access
I went with the xbox because i love final fantasy 3 & 7. The main developers that made final finatasy 7 basically signed onto microsoft and wont be making games from square enix or ps anytime soon. They came out with lost oddessy which is an awesome game.
gta iv is pretty good too.
i hope you have a hdtv, 780 is ok but the 1080 thats to drool for