Sam's Club Plus member. With them for travel distance and didn't need to buy another bulk item retail membership. Use Scan and Go if I'm not using pickup. An advantage of Costco's if it matters to you: their fuel is Top Tier certified (proven to have a better detergent additive than government standard) while Sam's/Murphy USA is not.
We have had a Costco card since they put one out at Jordan Creek, we purchased a Sam's card this winter, when they had a special where we could sign up for $25 dollars for a year for new members. We have stopped at Sam's once since we purchased the membership, just prefer to drive down to Costco or purchase the stuff online and have them delivered for larger items.