While keeping those credit card accounts active may be good for your score, it could create problems in the future. One time I had applied for a loan for a purchace through a computer store. The loan was denied. Reason? Too much OPEN credit.
I had a few credit cards, all with zero balances. The credit agency thought that I was too great a risk for the new loan with all that open credit being available to me when I wanted to use it.
I canceled all those cards that I had not used in a period of time, and those that I had never used. It did not appear to have an affect on my score, and lowered the amount of available credit that showed on my reports, making my credit appear less of a credit risk. It also took away any temptation to use those cards, helping also to keep my credit in check.