personality fish

From everyone's experience what do you think the best nano reef safe fish, post your opinion with the size tank it lives in.

I was planning to add a 2nd smaller tank. But I am going to wait another year. So... I would like to add another fish (no aggressive fish) or so to my tank. Suggestions for fish with beautiful color (or pattern) OR fish with lots of personality please. Current stock 300 gal : Bluejaw Trigger...