Mod as community mod? Then it depends what "good" means to you. China with merchant ships or the Spain and China mod are there for you if you want to play those nations.
Kensai two mods add a lot of punch to playing Austria, Prussia, Japan.
All are different in size and purpose. The problem is, that most have been written for older versions of the game and might be downgrades in some regards, as some of the functionality found its way into official patches