The Perfect 5DMIII Lens

I'm looking for the perfect lens. On my 7D, I loved the 18-55 f/2.8 - it suited my work perfectly, was really sharp, fast, and affordable.

I currently have the 24-105 and it's not that sharp, plus I'm missing the extra DoF.

I also have the 50 f/1.4, which is great when the auto focus isn't acting up. Low keeper rate on this one.

I wish there was something like the 18-55 on full frame. I guess the 24-70 is close, but no IS and the price tag is insane.

Any suggestions?