I'm currently using a Cannondale F900 MTB that I bought almost 10 years ago for my commuting. I have it fitted out with some more streetable 1.5 inch Marathon tires. But I have to say, if I were to do it again, I would have a touring or cross bike for a commuter. But I was young, and at the time I had to have a really fast racing bike and a really cool MTB. I don't race anymore, and I don't go off road as often as I thought I would... so a touring bike would more fit my purposes... but I have to get around to selling the current bikes.