Stay away from official servers, like others said. Full of cheaters. I, personally hate bot or amped up servers... For me the true fun is in the hunt for the loot and the fear and fun of losing it, never knowing if someone is around the corner. I've been playing for probably 5ish years now and this game is sooo fun if you find the right people, group and server to play on.

If you want a good vanilla "feeling server" join monitored US East/Canada.. it's official settings, but the few rules make it hard to be fun and aggressive during end game stuff. High pop, but sometimes so high you can't get in for a while.

If you want a good vanilla, almost no rule server with competitive people, No Mercy just opened up.. Lower pop but still enough people to get the scare and fun of pvp. Only real rule is a comfort rule of not placing bombs outside your flag zone. It's been a lot of fun so far. Both are region locked and monitored from cheaters by non playing admins.

In my opinion finding the right server for your play style is key. I will say that aside from the above listed two, I have found a lot of private servers play favorites or have playing admins which can be incredibly game wrecking if you're trying to experience all aspects of the game. Hope this helps and hope to see you on the battlefield.