Which lens would you recommend?

Joined: 15 Feb 2007 Posts: 1

Does anyone have any experience with this lens?

http://www.amazon.com/Sigma-18-200mm-3-5-6-3-Optical-Stabilizer/dp/B000NOSCGM/ref=pd_bbs_2?ie=UTF8&s=electronics&qid=1199588501&sr=8-2

Or this one?

http://www.amazon.com/Canon-17-85mm-4-5-6-Stabilized-Digital/dp/B0002Y5WXO/ref=sr_1_27?ie=UTF8&s=electronics&qid=1199588977&sr=1-27

I have a Canon XTi that I am using for nature photography, as well as photos of my (active) 3 yr old daughter. I currently have a package that included 2 tamron lenses, 28-80 mm and 75-300 mm. I find the lenses are okay but the photos are not incredibly sharp, and they do not have IS which makes it hard to use the telephoto features without a tripod (which is hard to lug around with a 3 yr old!). I am looking for a good, general walk-around lens.

And to clarify, by looking in to the IS features, I am thinking of using it for the "still" nature photos, not of my 3 yr old :). I am aware that IS is for camera shake, not subject movement! Of course, a lens that can also handle taking great action shots would be preferred :).

Photography is just a hobby for me, but the idea of a zoom lens sounds nice for playing with macros.

Which lens would the experts here recommend? Or if there is another one for my needs I am open to suggestions!

As always, TIA!