What membership programs are the best for saving money?

[MoneyonmyMind]

Hi everyone!  I've been reading this forum for a long time, but I finally signed up so that I can actually be involved in the conversation.

I'm always on the hunt for the best loyalty and membership programs to save on:
Travel
Groceries
Gas
Everyday spending
Other

I've signed up for Credit Card bonuses in the past, I frequent CVS and Walgreens for their loyalty program, and I tried to shop Krogers to get points for gas.  I'm just wondering if there are other program out there that might help me become more Mustachian.  I've looked into AAA discounts, AARP, and things of that nature, but I can't seem to find any true savings in those programs.  Any recommendations out there?  What am I missing that's out there?

Thank you!!

[vhalros]

A Costco membership has saved me a lot of money, but if you search for other posts about Costco you will find that it can be a horrible trap if you are bad with impulse purchases. CVS and Walgreens usually don't have competitive prices in my experience.

[skinnyindy]

Museum and zoo memberships can be good for travel if they have reciprocal benefits.  Check your local places before you go on a trip, especially if you have kids.

[Platypuses]

My favorite is using the Amex Blue Cash Preferred card that gives 6% back on groceries, buying gift certificates with it at Krogers when they have 4x fuel points and using the gift card on an expense you normally would have.