I know exactly which game I’d sell. But that’s meaningless for you. You need more friends. I almost always have a few games at friends houses. They are people I trust, so it’s easy. I look at some pins as very long term ownership games. Games that I’ve lent out multiple times, and have loved when they circle back to me later. When I get them back, it’s like getting a new game, but one I know I love.
Never sell a game you love to play. Figure out another way to solve it. It also leaves your options open for later. Because eventually each game will get stale, and it will be time to sell it. If you sell it before that happens, you’ll just be looking for it later.