Cancel & Re-open:
AAdvantage
SPG
AMEX PRG: I'm waiting for the next big bonus
United Explorer: All the same benefits of Sapphire minus the free bag or lounge pass.

Keep:
Delta Platinum: Provides yearly companion pass certificate
Sapphire: Keep Chase UR benefits, plus the card is too thick to cut up.
Ink: 5X at office supply stores that I buy gift cards with.
Club Carlson: Just got this one, but It comes with free hotel nights plus gold each year.

Actually, I just called to cancel the Delta Gold AMEX card because they got rid of the companion ticket benefit. They upgraded me to the Platinum card and as a perk gave me another companion ticket upon completion of the next billing cycle plus another one in February when my annual fee is due. I took that deal.. I live in Hawaii, so this perk is quite valuable.