Tough question.
Often what you don't have around is what you like best.
My first random thoughts (my basis is nationalities I've seen dozens of women, so this leaves out India, Kazakhstan -I've seen a couple of them, incredibly beautiful: a mix of Russian and Asian- or, say, Tunisia):
The top would be:
Brazil (as cadeiras das garotas brasileiras... mmmm
)
Cuba (a similar, glorious, mix)
Czech Republic (I was amazed)
On the next, high, level, I'd put:
USA (they've got all kinds, all races of women, very beautiful until they start bossing you around
)
Southern Spain (the more moorish, the better)
Southern Italy (same as Spain; many Northern girls are washed-out blondes)
Argentina (even if many of them look alike: more variety would have been welcomed).
...
Some girl watching (or "male chauvinist", depending on your point of view) statistical confession:
The other day, I was walking through the streets of my city, and I decided to grade all the women of passable age I saw on the streets. The results were dismaying: 10% pretty/beautiful; 35% OK; 55% homely or plain ugly.