Best expansion for casual players?

Hi everyone, I've just returned to wow after several months without playing. I'd like to create a new character (warrior, rogue or hunter) for PvP and start again in TBC, Cata or MoP (I don't want to play in WotLK).

I know that WoW consume too much time, but I'd like to know your opinion about which expansion (TBC, Cata or MoP) is more focused on casual players.

Thank you.

Mop is the most complete and balanced expansion, best choice for casual player.

Out of the expansions we have: MoP definitely offers more content to the casual player. Cata is second to it.

Going forward in WoW's development, Blizzard put more effort into providing more content for the casual player-base, as it is the largest part of the game's community. So you can generally expect that a newer expansion will offer more for you to do.

Legion :P

Definitely not TBC :)

I played Wotlk when it was the only expansion here and I know for sure that for a casual player it's no good.
Now I'm a casual player and play MoP.