Bartok wrote the third concerto for his wife to play (and earn some income) after he was gone.
My favorite versions of the set are in the following order:
1st - Zoltan Kocsis / Ivan Fischer on Philips
2nd - three way tie; Anda / Fricsay on DGG, Jando / Ligeti on Naxos, Sandor / Gielen & Reinhardt on Vox.
I like these pieces a lot and enjoy comparing versions.
As you can tell from my choices, I prefer performances by Hungarians.