Do you use a credit card? If so, which one(s)?

[SnesTea]

I'm interested in credit cards, cashback, travel points and the like. I find it very fascinating that there are so many credit cards out there. All of them seem to have their own perks, benefits, and privileges. Which credit cards do you use?

I personally use American Express and have a backup VISA and Discover. AMEX just provides a lot of cool things that add up over time like their FHR program for travel. It's nice getting a late check out and a credit to use at the hotel bar and breakfast everyday. The wife and I travel about 4-5 times a year and the benefits really add up, even when you subtract the annual fee :D