If you happen to want to play outside of Europe, Brunei. It starts out slightly stronger than its immediate neighbors, but not so much so as to make fighting them boring, and once it unites its island is in a good position to expand north into the Philippines or east to Sulawesi. Is in a pretty rich region of the world, so you won’t be too fussed about maximizing every ducat, and is island based so you can deter invasion by any stronger power you might encounter by building up a good fleet. Has the potential to form Malaya, if you want to go for that. Also in a good spot to benefit from colonizing if you want to do that.

France or PLC?

You’re pretty dominant in your region of Europe but you have at least two different directions for expansion

I would recommend the already recommended nations, especially those that got huge in history, like the Ottomens. Hell Spain might be nice. Building a huge empire full of goldmines. That could never go wrong.