Technically not my area, but mangosteen. Mostly grown in South-East Asia, it's a sour sweet fruit with the texture and structure like a soft orange, and one big seed per segment. It is seriously delicious.
I fucking hate the seeds though. It's like, you're getting to this sweet and juicy part of the segment's flesh, and then the seed just stops you cold from enjoying the fruit.
I hear you. The rare occasion I'm in Singapore I will buy a whole bag and devour them all over a few days.
And when I see them where I am (also often golf ball sized), I message all my SEA friends with the location and price so they can descend like a flock of seagulls.