I just closed 4 cards last week, so I know what you're going through!
It's harder in your case because your cards have much higher limits opposed to the cards that I closed. But let's look at it this way... If you don't need the available credit to keep your utilization in check (I'm sure you know that they'll still report as positive accounts for many more years), there are a few I'd eliminate.
Sams club - Useless for anything other than it's high limit. You can't use it anywhere other than Walmart or Sams. And by the look of the cards in your sig, you have cards that are much more beneficial to be using.
Walmart - I would keep this one open, over the Sams card. You have the financing available to you, 24 month financing is a nice thing to have. You never know when it may come in handy. Plus it's an actualy CC, not limited to 2 stores.
Sportsman - You don't use it, the limit is relatively low compared to the rest of your limits, I'd cut it.
Capital One - I'm assuming it's platinum, which I see as the entry level score building card. You've gotten out of it what it's worth. It serves you no purpose anymore, and has a relatively low limit to many of your other cards. I would close it, or try to PC it to a Venture/QS.
JCP - Meh, it's an MC, it has a good limit, but if you never use it, and the rewards are lack luster, I'd probably axe it.
