Best Nations

I'm currently playing Sweden and have reached 11.0 Air RB and 7.7 ground RB. Everyone said that the ground tree gets really fun from this point and while I do somewhat agree I'm also a bit underwhelmed. I'm just not a big fan of the British imports.

I'm a bit bored of Sweden and looking for alternatives. Any good nations I should grind which are at least decent in the current meta and have good lineups? Thanks!