Ok, heres my dilemma. I will be buying my first lens someday in the near future and I want to get a good one. Most people have been saying that I should get a wide angle zoom. I was originally looking at the Canon 28-135mm lens, but some say that might not be wide enough on a 1.6 body. So then I started to consider the 17-85mm. Both of these lenses have IS, which is a good thing, but the 17-85mm is a little slower than the 28-135mm. I know that the 17-55mm is f/2.8, but that is a little out of my budget; I would prefer not to spend much more than the 17-85mm costs (not yet) . Then I started looking at third party lenses. I found the Tamron 17-35mm f/2.8-4 and the Sigma 18-50 f/2.8. How does the Tamron and the Sigma stack up to the Canon? Would I be sacrificing image quality by not going with Canon? I dont want to spend more than $500 just yet, but I do want to get a lens that I will happy with. Any ideas anyone? Thanks.