Just to add to the chorus...
I had bought both the 24mm f1.4L and 35mm f1.4L lenses and absolutely hated the 24mm. I just didn't find it sharp. I eventually sold it.
The 35mm f1.4L on the other hand is a real joy... beautifully sharp. I love it!
When I need wider, I use my 16-35mm f2.8L, but as others have mentioned, it's not as sharp as the 35mm. And for wider still, my only non-Canon lens is the Sigma 15mm f2.8EX diagonal fisheye. That lens is surprisingly good also. (But it's a fisheye.)
If you find something wide® that you really like, I'd sure like to hear about it (as others probably would as well).