I have a Trek720 that I picked up at a garage sale a couple weeks ago and I LOVE it! It was only $50, and a steal at that. I was commuting on my road bike because it's so far, and I may actually have to start doing that again (new road bike= lightweight and I can go faster). The Trek is heavier and sturdier, so it's now used as my errand bike/grocery store/all purpose bike (I rode it 11 miles downtown today to go to the marathon expo).
I'd scout out some used bikes on craigslist and get a good tune up done. You might be able to get an even nicer bike than you would if you got one new. If you really want a new one, I've been lusting after a Kona for some time. Those are really sweet looking bikes!
Good luck, and do show us pictures when you make your decision!!!