I would wait for the next JJP game because it will be a theme you love. JJP games are loaded with toys, and are extremely deep. Pirates is incredible, but if you want one and only one pin, I would wait for jjP to release a dream theme.
I am new to the hobby, but I play on location a couple times per week, and the JJP games—particularly the Hobbit and Pirates—feel like a journey that would be perfect for an in-home pin, and have the depth to provide staying power.
Star Trek is a great pin as well.
I know this is not a popular opinion here, I would avoid Spiderman and X-Men at all costs in a home that can only house one pin.
Either way, I imagine you will eventually sale or trade your first pin, or better yet, move things around to find space for another.