Better question is what are you going to be taking pictures of? That way we can tell what focal range is good for your application.
This is the only link you need Phil: Main List with Links - Canon Digital Photography Forums It shows the lenses, the price and sample pictures.
Be sure to check Craigslist and POTN for a nice used one if you want to save a few dollars. Mostly anyone who buys these lenses take great care of them.
get yourself an account on fredmiranda.com: Specialized in Canon - Nikon SLR Cameras, Forum, Photoshop Plugins, Actions, Reviews, Hosting and Digital Darkroom too. their buy&sell section is legit
I've got the 24 to 105 lens and I love it, I've got a few prime lenses now but I always go back to my 24 - 105 all the time, one of my favorite lens. I'm really enjoying my prime 24mm lens, very versatile lens :thumb: You wont go wrong with the 24-70mm lens....now just get the lens and get me some pics..you know what what I'm talking about
don't know much about canon, but anything 2.8 should be swell to get nice shots of kids and action in low light...