Well. Saab 340A.
I am sure anyone who researched X-Plane addons market, even briefly, is aware that Saab 340A is considered something on coloquial "next level". Because it is. It's a study sim, very realistic model of a very interesting and fun aircraft. It should (and is) a benchmark for every other aircraft addon. I couldn't recommend this plane more. It's challenging but really satisfying. Just a complete, high quality aircraft. 5/5.