I don't wear anything bicycle specific for either commuting, around town, touring, or just long rides. I am perfectly comfortable in my normal clothes. Before I buy anything I always make sure that it will also work on the bike (ie long arms, long back, stretchy, no seems in the crotch) because my bike is my main source of transportation.
IF you start to think about it, in a lot of ways there is also car-specific clothes. I mean, without the advent of the car how practical would it be to wear min skirts, high heels or any of the other impractical crap that most people wear? Next time your out and about take a look at what the car drivers are wearing and ask yourself if they would dress exactly the same way if they had to cycle, take the bus, or walk. Everyone wear transportationaly specific clothes!
I just don't choose the flaming, superhero, Richard Simmons look.
Here is me last weekend on a group camping trip. The ride was a bit over 120k to an island off the west coast of Korea. If I were alone I probably wouldn't have even worn the helmet but I didn't want to get chewed out by the safety-nannies on the ride.