Which PS3 is better

Which version is better is up to you, depending on where you live you have the following options:

PS3 80GB (US)
80GB HDD, Card Reader, Backwards Compatible with PS2 games, 1 free game (Motorstorm)

PS3 60GB (discontinued, search the stores if you want one)
60GB HDD, Card Reader, Backwards Compatible with PS2 games, 2nd controller, 2 games for free (Resistance and Motorstorm)

PS3 40GB (Worldwide)
40GB HDD, No Card Reader, Not Backwards Compatible

I won't write about the 20GB since you probably can´t find one anymore.