Which lens for the EOS 350D??

I am about to purchase the 350D but everything I have read suggests that the lens that comes with it, isn't that great, so I am thinking of just buying the body and getting a separate lens. Now, that's the tricky part- which one exactly???
I am not going to be photographing anything inparticular, but really a mix of portraits, landscapes, sports.
I have been looking at both the Tamron 18-200mm and the Sigma 18-200mm and cannot really decide which one is better, or if perhaps there is something else out there which would suit me better. Any advice???

For general photography either one would be fine, I've used a Sigma 18-125mm for almost a year now as a general lens. Also www.bhphoto.com has a kit with the Canon 17-85mm EF-S IS f4-5.6 lens. Another great general use lens.

Here are a few suggestions:
Tamron 17-35
Tamron 28-75
Sigma 24-70

These are all good starter lenses.

Go for the tamron 18-200. I had the 28-300 on my film when I had it which is close to 18-200 with factor, and I thought it was great for starting out.

It all depends on your price range.
I got 350D recently and first got the EF-S 17-85 IS USM and EF 50 F1.8 II with it.
17-85 is great as a generic walkaround lense and on the 350D it is an equivalent of 28-135 focal range of a 35mm camera. IS works well in allowing you to handhold at quite slow shutter-speeds. And 50 1.8 lens is just a fantastic bargain - sharp, lightweight, compact, cheap and performs well in dark environments.
Then, on the long telephoto range I just added 70-200 F4L. What a lense!!!