In reply to Ricky Nos:
I've had a look at a the 1.8, courtesy of a friend. I've also seen a lot of shots taken with this lens and can honestly say that, for the price, you can't really go wrong with the IQ. However, I personally prefer the 35mm f2, for most of the shots where I might consider using either of these lenses. The 35mm has a more "natural" focal length and is better built than the 1.8 (possibly sharper, as well). I can't comment on the 1.4, of course. I would possibly prefer the 50mm primes for some shots at gigs, where the longer focal length might be more important.
Just a little extra food for thought...
J