IMO a fisheye will set you back a big wad of money and has limited use.
Second the 10-22 EF-S. Though I had flare problems with mine.
I've "test driven" the 17-55 2.8, and while it's great glass, it really is VERY plasticky. It doesn't inspire confidence at all and is quite over-priced IMO.
The 17-40 has loads of fans and but I've never tried one
One to think about that's not on your list is the 14mm 2.8L. This is a very good lens indeed for a 1.6 body. Its wonderfully sharp and the slight but noticable,light fall-off and barrel distortion are much less evident on these bodies than a FF SLR.
However the best of the bunch is the Sigma 15-30 3.5 - 5.6, which can easily hold its own with any WA zoom, and, OH LOOK - I have one for sale right here!
Half the fun of ownership is the hunt!
Enjoy.
Peter