Best Canon walk around lens to buy?

Pretty simple, if you are just getting a camera to take candid photos with and random things mostly just for fun then the 18-200 is a good idea. One lens for everything. But if you are really into photography the 17-40 f/4 is a much higher guild quality, and will be much sharper with better color. Most serious photographers will switch around a lot before they find their "lens" that works best for them all the time. Mine is a 35 f/1.4. I dont at all miss not having a zoom at all. Of course If I am working then I also have a 70-200 f/2.8 but otherwise its just the 35.