Brazil.
A lot of games, in fact you have no time to play friendly games. Games of state leagues in January - March, and other year for Serie A/B/C, Copa Brazil and SA Cups.
You have the limit for foreign players
Add top 6-8 of UEFA federations as playable, and you will hate transfer windows
Brazilian clubs pretty rich, top clubs have ~35-40 mln euro per year just for TV broadcasting.
Excellent opportunity to use players of all ages from 16 to 36+ years old
At some point this will become easy, since the AI has a hard time keeping up with the constant sale of stars. But this is a very rich and interesting league