I have both the 10-22 and 17-40 that I use on my 50D. The 10-22 could easily pass as an L lens, but overall it still lacks that wonderful L contrast. The 17-40 with a CPL is dangerously good.
Although I don't think I'll ever sell my 17-40.
17-55 is also an L in disguise.
Can't comment on the 24-70 and 24-105 since I haven't used them.