What it's better, Grand Turismo 5 or Forza Motorsport 3?

i'm thinking to get a ps3 or xbox 360, however, each one has it's uniqueness,

Xbox 360 has Forza motorsport 2 and 3, but i'm still not played. Is it good game?

ps3 has gt5 , i rented one time and i adore it,

i want your opinions, which it's better.What it's better, Grand Turismo 5 or Forza Motorsport 3?
forza motorsport 3
Gran Turismo 5 has over 1000, fully customizable cars, 'nuff said.What it's better, Grand Turismo 5 or Forza Motorsport 3?
I would say gt because ps3 has really good games an gt is fun
get a ps3.. you'll also have killzone 3 and infamous 2 and mass effect 2 to look forward toWhat it's better, Grand Turismo 5 or Forza Motorsport 3?
gran 5 because they have better graphics, more realistic cars and real tracks and the music is great
forza 3 nuf said xD
i would say gran turismo ...but! i would get the 360 cuz turismo wont last forver and 360 has some good games and great online