Bueh B. , Oct 22, 2010; 01:28 a.m.
However, there seem to be 3 50mm lenses: a 1.2, 1.4, and 1.8.
Don't forget the discontinued f/1.0 and the f/2.5 macro. And Sigma and Zeiss make highly-regarded 50mm primes, too. The apertures are different, but so are build quality, features, handling, weight and obviously cost.
If you cannot afford the zoom, I guess the 1.2L is out of your price range, too. Funds permitting, this would be my first choice, and the Canon and Sigma f/1.4 lenses second. If I hadn't already the Canon I would probably prefer the newer Sigma. The f/1.8 version is also very decent, but lacks full-time manual (FTM) which I want -- so the macro and the manual focus Zeiss are not for me, either.