Some of the fish I really loved in books weren't as amazing when I saw them in person so my holy grail fish is very common, pretty cheap and super hardy. I got mine when I was going through treatment for cancer, basically as something to cheer me up a bit and give me something to do. I'd always liked them but never really thought of owning one but now I would be happy if it was the only fish I ever had.
So mines a marine betta, the fish I needed at that stage of my life, but I wouldn't say no to a pair of crosshatch triggerfish.
If you're lucky you can train marine bettas to be out during the day. I did it very successfully with mine, he's out constantly and follows me back and forth when I'm near the tank. Took a lot of patience and a dim, quiet QT for him to become comfortable with me. When he started eating from my fingers (and he still does) I knew it was going well.I love this also. I have keep pair of Marine Beta. I would love to get a FineSpot MB in the future. They are beautiful. They are difficult to get a picture of for sure, only come out to the open in the evening and night. Their behavior is so very interesting.
Tried doing the same with a marine betta to be put in a display at work. I got him to eat from my fingers sparingly in my QT, but he was much larger to begin with so he still hides a decent amount. I can tell he's curious though and I see him multiple times a day at work.