Prior to the introduction of the Sigma 18-35mm F1.8 DC HSM ($799 direct) lens shutterbugs with APS-C D-SLR cameras had to make a choice when it came to lens functionality. You can go with a zoom lens and cover a range of focal lengths, but even top-end models only opened up to f/2.8.
Sharp; Wide aperture; Reasonable price tag; Available for several camera systems
Big; No optical stabilization; Some wide-angle barrel distortion.