Here's what my daddy just bought for himself, for commuting. It's one heckova steal:
http://www.bikesdirect.com/products/...quila_xiii.htm
If you plan on doing "trails," take a look at cyclocross bikes. I think they're by far the best for... everything!
EDIT: This bike is similar to the Trek, except A LOT better for a lot less money. Also notice that it fits all different width tires for different seasons and purposes.