My 2 Cents...If you're on poor/nonexistent pavement you need the wider tires such as on an MTB. If you have good pavement and/or are in hilly terrain, or fairly regularly have windy conditions, you'd be better served by a lighter road type bike with the skinnier tires. The best all around commuter (in my opinion) is a touring bike set up with fenders and racks. Ideally I would suggest you should try to find a good quality used touring bike. A good 5 year old bike might only cost you ~ $200 or so. New, prices start around $500minimum.