See head - see wall, see Layston beat head against wall....
I already know that my next two lenses are a prime (30, 35 or 50mm) and the Sigma 12-24 (if I get my way). But I'm beating myself up about which prime to pick up first. I've owned a 50mm f1.8 FD for a long time and love the lens and focal length. I don't have a prime yet for my Canon EOS cameras. Yes I could go and pick up the 50mm f1.8 without really hurting my wallet, but I'm trying to be judicious in my lens purchases. I also want a macro, but I'm thinking that will have to wait until I can afford the fabled 100mm f2.8.
So if you were going to buy ONE prime, what would it be. The nifty fifty, the 50mm f1.4, the 50mm f2.5 macro or Sigma's 50mm f2.8 macro (which does 1:1)?
Canon 50mm f1.8

