This will turn into a car versus bikers thread unfortunately. But from my experience, commuting by bicycle has been one of the best decisions I've made.
I started out in the suburbs, commuting by car 50 minutes each way. Over the years I kept moving closer and closer to the city and my job...which is pretty much the opposite of what Americans tend to do. Eventually I ditched the car commute for public transit, and finally ditched public transit for a bike.
Being in a car sucks. You are isolated, stuck in a behemoth monster of a machine in a sea of other machines. Your isolation makes you feel anonymous, and anonymity gives you the freedom to seethe and yell at other drivers who dare to go slower than you, faster than you, or God forbid, try to get in front of you.
On a bike you are out in the open, feeling the weather and the wind and the change of seasons and daylight. You interact with people way more, and on much friendlier terms...after all, you're no longer protected behind your locked metal box. You actually have to act like a normal, decent human.
Now yes, there are the Lycra ads-on-butts boys that pretend they're in a race, but jerks abound everywhere in every activity.