I couldn't even afford a Canon version, so I opted for a Super Takumar 50mm f/1.4.
I started with the EF 50/1.8II, then went to Super Tak 50/1.4 (but now I'm on the FL 55/1.2).
Super Tak is a bit low-contrast at f/1.4, but at f/2.0 it beats the EF 50/1.8 II at f/4.0.
Built like a zeiss, silky-smooth focus, as small as the EF 50/1.8, get a slightly yellowed one and your portraits just look amazing.
You can't do much better for less than $100 if you're a bit patient on ebay.
MF is not for everyone, of course. If you definitely need AF i'd probably be heading Sigma-way for IQ (although the AF isn't very reliable from what i've heard).