I love my Discover Card. I was not interested in getting a Discover Card until I heard about their cash back program. I love this program because they pick a category, usually for a 3 month period, that you gives you 5% back. There is a cap, usually about $400. I wish they did not have this cap, but I guess they wouldn't make much money if they didn't. What is so great about their rewards program is that you can redeem your cashback for gift cards. They have a great selection of gifts cards and most are a dollar for dollar trade, but some are not. I can actually double my cash back with some merchants. I usually cash in my money for Sharper Image cards. If I cash in $40, I actually get an $80 gift card.
The downside of the Discover Card is that the cashback is less than 1% if you are not doing the special promotion. You also have to go to the website and sign up for the 5% promotion, or you don't get it. I don't know what my interest rate is, but I think it is kind of high. I always pay the bill off when I get it.