Found this on the FM forum, another vote for the 28-135, You can pick up a good used one for under $250.
"Anyone feel that there are underrated gems in the Canon lens lineup?
I'll stick my neck out, I bought a Canon EF 28-135mm f/3.5-5.6 IS USM because I needed a cheap wide range zoom for a particular project. I didn't expect too much from this lens because it was affordable, not an L, with a wide range. Also I use it on a 5D2 which is sure to test any lenses' resolution, and with a FM review rating of 7.8 I didn't expect anything impressive.
Well, as you can guess I am blown away by this lens. While no lens is perfect, at f8 this cheap zoom looks satisfyingly sharp to me, and I am a completely retentive pixel peeper, my middle name is 100%."