I always use AMEX if buying anything big or prepaying....purchased a cruise for my wife and myself two months before 911.....Cruise line went bankrupt.....AMEX ate it not me......
Plus I like the percentage back.
Often AMEX can't be used, then MasterCard comes out for those big purchases.....ok, so I use it for fuel too.
In any event, I NEVER buy anything on credit I can't pay off at the end of the month.
For smaller purchases, I use cash (groceries etc).....I have a good Credit Union that has reciprocal agreements with other CUs, so no fee at the ATM.