I'd like to purchase a 50mm lens. It seems there are 4 options from Canon:

Canon EF 50mm f/1.8 II Lens
Canon EF 50mm f/1.4 USM Lens
Canon EF 50mm f/2.5 Macro Lens
Canon EF 50mm f/1.2 L USM Lens

Any suggestions on which one should I pick.

I know the f/1.2 L is much more expensive, does it provide much better quality images?