We've been here before, but I'll throw the Sigma 50mm f/1.4 into this discussion just for the hell of it. It is my quality 50mm, and it's nice that it shares the 77mm filter thread woth most of my other lenses. For travel I have a 50 mm f/1.8 Mk I. These are my workarounds considering the current offerings of Canon 50's.
I am a fan and own the Sigma 50mm f/1.4....guess we got lucky and got good copies... Love this lens....BUT...it could be that with Sigma's new commitment to the craft we may see an Art series 50mm and if it is anything like the Art 35mm f/1.4...I think I would be all over that!!!!!!!
Canon has a lot..but it just doesn't have it all.
5D Mark III, Canon 15mm f/2.8 Fisheye, Canon 17mm f/4L TS-E, Canon 16-35mm f/2.8L II, 21mm f/2.8 Zeiss, Sigma 35mm f/1.4, 24-70mm f/2.8 II, 50mm f/1.4 Sigma, 85mm f/1.2L, 100mm f/2.8L Macro,70-200mm f/2.8L IS II...1.4x converter III, and some other stuff.....