Lens dilemma...help please!

I currently have a 17-40 and 70-200f/4L IS and absolutely love both of them. But of late, i am looking for walk-around lens for my 50D. Not looking at anything expensive. Looking for advice on what may be a good option. I have listed a few options below. Please let me know what your thoughts are

1) Canon 17-55 2.8IS (too expensive)
2) Sigma 17-70 (read mixed reviews about it)
3) Canon 18-55 IS (read mixed reviews about it)
4) Canon 28-135
5) Canon 24-105L (too expensive)

Appreciate any response.

Thanks!
Vinay

You may want to consider the Tamron 17-50 2.8. I picked one of these up a few months back and have no regrets.

what don't you like with your 17-40 that you want this lens to do? To me, owning the 17-40 I'd rule out any of the 17/18-50/70 options you have listed unless you sell the 17-40 to do it.

Like i mentioned in my earlier post, I am looking at slightly longer reach as a daily walk around (even though the options I have listed say otherwise). I was hoping that some of you maybe able to provide information on what may be a good option for a longer reach walk-around lens.

Would taking a few steps forward using the 17-40, or a few steps back using your 70-200 not suffice?

While I just sold it, I enjoyed and used my Canon 28-135 for a walk around lense. Fairly lightweight, produced great colors, AF was quick. I was very pleased with it.

I had a Canon 28-105 EF 28-105mm f/3.5-4.5 It was a great lens. It's taken over 5000 pictures to date and going strong.
I gave it to a friend when I upgraded to a 24-105 f4L. She is very happy with it. It's her main walk around lens

Terry

Tamron or Sigma 17/18-50 f/2.8 - great walkaround lens.

I used a Sigma 18-50 for a year or so and loved it. Stumped up for the 17-55 IS and love that too... but there isn't much between them apart from the obvious IS and USM.

I agree with terry_glover, I too had the 28-105 f/3.5-5.6 and I loved that lens for just walking around. I sold it recently when I upgraded to the 24-105L and wish I still had it at times.

My main walk around lens (at birthday parties and fairs with the kids and the likes) would be my Tamron 17-50 f/2.8, I have had this lens for about 4 years and it is spot on every time.