Top Three maps on this game are (my opinion )

Cario Bazaar and Siege of Cairo are two of my firm favourites too. Picking a third one is harder, but it'd probably be Hengetal Base for me.

I love Siege of Cairo, I think it's a gem of a map and the true highlight of the initial offering, but I can't play it anymore: it seems to attract all the try-hards, what used to be fun has become a bunny-hopping frenzy. Maybe when the community servers come I'll get to enjoy it again. 

The other two for me would be Tsuru Reef (another gem), and either Manhattan Bridge or Golmud.

Liberation Peak would be special (in general and to me: I lived 4 years in Tajikistan and I can attest it looks pretty accurate) if it weren't for that dumb mountain in the middle turning the whole map into sniper alley. Close, very close, but no cigar.