There is no real reason to ever close a card, unless it has fees. Two bank cards and four store cards aren't excessive at all. (Obviously you don't have problems controlling your charging behavior, or with your ability to repay, etc.) But if the presence of the store cards just bugs you to death, you can close them.
Be aware of possible effects on your revolving util. They will continue to support your average age of accounts as long as they remain on your reports. This should be 10 years, although with Equifax, ya just never know these days.
In your position, I would definitely keep the cards. You're probably OK with using a store card once every six months or so, although once every four months is safer. Use each bank card at least once a month (a tank of gas and so forth), because bank cards get closed by the lender for disuse much more quickly than do store cards.
Read fused's "Closing Credit Cards" in my siggy below. His post is great for helping you think through something that is pretty counter-intuitive.
* Credit is a wonderful servant, but a terrible master. * Who's the boss --you or your credit?
FICO's: EQ 781 - TU 793 - EX 779 (from PSECU) - Done credit hunting; having fun with credit gardening. - EQ 590 on 5/14/2007
