Have 20D body. Need lens advice

Just purchased a 20D. Will be using it for kids sports, shots for magazines (still and action), general family pics, etc.

Thinking a 17-85 range zoom will be my best overall lens choice but open to suggestions.

I am not stuck on Canon lenses and am hoping for input on others such as SIGMA and Tamron or equivalent. Basically want the best lens I can buy without paying extra for a name. Budget is roughly $350-$500

Thanks in advance.

With your budget and the kind of varied photos you want to shoot, I'd say the best lens you could buy would be the Canon EF 17-40mm f/4L. Canon L glass really is wonderful. Plus, the fairly fast f/4 aperture and excellent autofocus that lens offers will serve you well for action photos. I've been using a Tamron 28-75mm f/2.8 Di lens on my 10D and I've been more than happy with it, although it doesn't offer really wide angle capability. For that, I pack the Canon 15mm fisheye.

You bought a really nice camera with a great sensor. Don't cripple it by buying cheap glass. Buy the best lens you can afford - and then some. You won't regret it. If you buy a cheap lens, you'll likely be wanting to upgrade soon. And then you will have spent more. Spend more now instead.

The Tamron XR-Di seems to have some QC issues, but a good copy is very sharp. It does impart a very slight magenta cast, but not overwelmingly so. The 17-85 you mention has a great range, similar to the range on the Canon 28-135 on a film camera. The Canon 17-85 is a decent lens, but not up to the optical standards of the 17-40 or Tamron 28-75 that Photo-John mentioned.
If you are into sports photography, you will need something longer than all of the lenses above, you will be surprised when you see how small a subject with any distance from the lens is in the frame. IMO 200mm is the minimum length for sports photography and even with that length you will have to be fairly close to the action. Any of Canon's 70-200 Ls are very sharp and produce excellent images. A good all around combo that gets you from wide angle to short tele would be the 17-40 f/4L that P-J suggested and the 70-200 f/4L with maybe a 50 1.8 or 1.4 to fill the gap and provide low light coverage. Like P-J said, make the glass purchases your #1 expense, with what you have left over, purchase your body.