I like the Human areas, but there are a bit to many Centaur there for my taste. And i dont find them a very interesting enemy to begin with. Just my opinion ofcourse, i found the Skritt to be much more fun (quite a funny enemy to fight).
Bandits where "okay", wasnt fighting them all the time. I guess if there were as many as Centaurs id get sick of them aswell, altough overall a more interesting enemy then the Centaur. Altough i got sick of them in the storymode very, very quickly. Partly because they are dumber then spit. And i dont mean combat AI, just... oblivious to the obvious.
I found the enemies that the Sylvari face to be more interesting. Or the Charr.