My personal favorite is the wyvern. They attack almost 3 times for every attack an equal leveled drake does, and more than 3 times for the equal level serpent. But I do keep a serpent in front to tank damage.
This isn't really a big issue, but it is a little confusing. After I conquered my first 5 or 6 regions, the rest of the regions I conquered remained as white squares instead a turning to the light green. Like I said not really big problem but it means I gotta check regions over again to make sure I actually took it.
 "Dragon Fortress"){kind=icon}
 "Trimps"){kind=icon}
 "Clickilization"){kind=icon}
 "Mastermind: World Conquerer"){kind=icon}
Fixed now - thanks for notice, the problem was one wrong number in code :)