EF Lens Recommendation

I plan to buy a Digital Rebel XTi & would like some recommendations on an EF zoom/telephoto lens (somewhere in the range of 35 - 100mm). I am looking for a lens that is well-matched to use the capabilities of this camera & provides clear, sharp images. Also, I am not opposed to aftermarket lens.

Thank you for your help.

35-100 is kind of an unusual range for an APS-C camera. This is slightly longer than normal to telephoto. If you have a 35mm film background this would be equivalent to a 56-160 range on 35mm format.

Do you plan to shoot indoors at all? Would this be your main lens, or do you already have one and this is an additional telephoto.

For the former, look at these lenses which are all generally recommended:
Tamron 17-50 f/2.8
Sigma 18-50 f/2.8
Canon EF-S 17-55 f/2.8 IS USM
Sigma 17-70 f/2.8-4.5

For the latter consider
Sigma 70-300 APO
Canon 70-300 f/4-5.6 IS USM
Canon 70-200 f/4L IS USM
Canon 70-200 f/2.8 IS USM

2 questions.

What is your budget?

How large of prints are you planning to make?

As stated above, a little more info would help people give you more specific recomendations. How much do you want to spend and what do you shoot? Not really knowing either, I could recomend the Canon 24-105 f4L IS. If you scroll down through the first 2 or 3 pages of this forum, you'll find more info than you could want about that particular lens....It's been really popular the last week or so

BTW....Welcome to POTN!