The bikes suggested thus far are solid candidates. CX bikes seem to translate really well into commuters as can be seen in these forums, and for good reason - they offer a great blend of performance and utility.
"Randonneur" and touring style bikes offer more utility, at the expense of a smidge of performance, and numerous models have discs. Trek's Portland model comes to mind.

Another option in the cx vein: http://www.bikesdirect.com/products/...ane/outlaw.htm
Nice bike for the money. I'd lose the brifters and sell 'em as new and install bar-ends. Single eyelet in back means fenders and rack would both be mounted there with a little longer screw (rack first, then fenders).

What's the catch? You'll have to spend about 20-30 minutes assembling it, and it is a good idea to verify the spoke tension and grease in hubs/BB/headset. Though there are those who may argue the point, I've personally been satisfied with my BD purchases (2 bikes so far), but the tradeoffs are real. I've been wrenching on bikes (professionally for a while and as a hobby) since the 70's so it is a non-issue for me. YMMV.

With a clean slate and reasonable budget, there are many options. I'm partial to internally geared hubs but will not post a litany of options there. I've already done that elsewhere on these threads