Like.
if there's no strategy to it:
Possession
Rebuild
Sauna/Avanto (does that count as two??)
Urchin
Tournament
It's more interesting if you get to change each game. Generally you want to eliminate high skill cards and cards that require strong tactical decisions if the opponent is better than you, and you want the opposite against weaker players. Also, if you know you are second player, you should ban cards that greatly benefit first player (Governor comes to mind), and first player should ban cards that favor longer games. I suppose first player should also ban Tax.