For me, I think we used Skippy creamy peanut butter and Smuckers strawberry jelly (not jam or preserves). Really soft bread, like Wonder bread, tended to tear when spreading peanut butter, particularly the crunchy style. (One solution was to toast the bread, which resulted in slightly melty peanut butter that was actually kind of nice.)
When I was a child, any time bread was involved, Mom insisted that butter had to be involved also. Sandwiches and toast, naturally, but also things like dinner rolls. Just about the only exception was when she made garlic bread, when she used garlic spread.
As an adult, I no longer feel the need for butter on a lot of sandwiches. And to bring this post back to the subject matter, it is especially not needed on PB&Js. After all, “butter” is right there in the name of the peanutty substance. 
Skippy’s chunky and cherry preserves, in a fresh pita. You don’t even have to spread them - just put a lump of PB and lump of jam in the pocket and squeeze until they’re evenly distributed.
That sounds really good. I wonder if i can find some decent cherry preserves…
Wonder no more, pjd.
It tastes not unlike the strawberry jam (jelly) version, peanutty and fruity.
My favorite is red currant jelly (which i make, from my sister’s crop, each spring) with Skippy extra crunchy peanut butter. The red currant jelly is tart enough and “bright” enough to give a nice contrasting note to the sweet sticky peanut butter, and i like the texture of “crunchy”. I put it on whatever sandwich bread we have in the freezer. That’s currently “Dave’s good seed”, which also has some textural interest. That bread is a little sweet on its own, but goes very well with pb&j.