I'm in the camp that only uses my towels once before washing them. It's how I grew up. When I was an undergrad, I would use them for a week before washing, but that was only because I had to use my dorm's laundromat, and I was trying to save money and time. Now that I have my own washer and dryer, it's fresh towels everyday for me and DH. We usually do laundry about twice a week to keep the hamper from overflowing. As for pajamas, we don't wear those, and we try to change the sheets every week (but sometimes life gets in the way and we don't get around to it until the second week).
There's no wrong or right answer for this one, as it's all about personal preference. In my case, there's no reason for me to have to reuse my towels, so I don't.