I think ALL fixed-focal length lenses are good, at least for films. For digital, some wide angles could use a redesign to improve, though. Even 35/2, 50/1.8 and other non-USM non-L lenses are really sharp at f/4 to f/8 range. After that, any difference to talk about is purely academic, or not even that.
The only EF lenses I would be very selective are the zooms. I would not buy any of the cheap zooms. Luckily enough, 17-40mm f/4 USM L and 24-105mm f/4 USM L are really good and reasonably priced, if you don't need f/2.8. I personally rather use primes than f/2.8 zooms, when necessary.