Quote Originally Posted by gryphonslair99
Can't comment on the Sigma, but I have the Tamron 17-50mm f2.8 and find it to be an excellent piece of glass at an excellent price. You might want to consider it as well.

Couple of reviews: http://bythom.com/1750lens.htm
http://www.planetnikon.com/Review-Tamron17-50mmF2.8.asp

Meant to mention, mine is the 1st gen for Canon. A couple of Nikon shooters I know have the Nikon version and love it. One has the 1st gen and one has the newer VC version.
Thanks, I will check it out, Jeff