Imo the best vanity pet for this is the Guild Herald. Someone should check if pet biscuits work on him since that'd be quite awesome (a huge orc as a pet carrying a flag). The only downside is the cooldown, but it used to be pretty cool in a raid when a bunch of people whipped theirs out at the same time.
I agree with pets being in the way in serious content tho. I remember back when we were progressing H Maloriac, i wouldn't dare to take out a pet even as a joke. The black phase was way too bad with all the spell effects hiding the puddles already.