The EF 17-40 has good build quality, but the Tamron 17-50 f/2.8 is longer, faster, cheaper, and has higher image quality.


The "IS" version of the 18-55 would give you image stabilization for a small price.


The 17-85 IS has longer range, but the aperture and image quality are not much better than the 18-55 IS, despite costing much more.


The 17-55 f/2.8 IS is obviously the highest quality combination with IS, but it costs an arm and a leg.


In short, you have to pick any two of the following:
  • Cheap
  • Excellent image quality
  • Image stabilization



If you pick "Cheap and Excellent image quality", you get the Tamron 17-50 f/2.8, but no IS.


If you pick "Cheap and image stabilization", you get the 18-55 IS or 17-85 IS, but no excellent image quality.


If you pick "Excellent image quality and image stabilization", you get the 17-55, but it's not cheap.