No LA? But LA is where all the fun thematic nations are.
Why not try Helheim? Bring glamoured death to them all! Or Mictlan? Giant sacred armies of doom!
Really, I'm not sure. What are you looking for? A good nation that fits your playing style and tastes (which, if that's your wish, then elaborate on them), a powerhouse nation that can crush all opposition, a nation that'll make'em think, a nation that'll help ease you in to MP...?
But if you're looking for a powerhouse nation, I would go with Lanka/Helheim/Mictlan/Sauromatia/Himmon.