Well, IF you happen to know that V's; W's and B's enjoy to trade places in linguistics, I think you can guess it now?

If you wan't a fun game, and just don't want to see lot's of well-known Eastern/Greek crappy units on your road to conquest -> the Aedui or Arverni are all yours. Economy is decent, but you really shouldn't overextend yourself.

Another fun faction is the Casse, but you need to have a bit of patience to really enjoy them. As soon as you've managed to take all of Brittain you've got an economy unlike anything else in the North & West. You've got plenty of sea trade possibilities, you've got fellow Celtice allies (Aedui and Arverni), and your military is pretty unique. (With all those sweet Champion units.)