What do a the best Alternate personality for rogues?

I don't think we know what this is yet .... but thoughts?

Best Persona for any of the 3 melee is probably gonna be something that can Molo effectively, like a Pet class or like SK or Paladin

Look at this from the prospective of usefulness to a group: if you have a group for your rogue, that means tanking and healing have been addressed in your group, and probably you are in there for a dps of your rogue. In such case - go with a ranger or a zerker. Your group will still welcome you and you can benefit from chain-class gear exchange.

If your rogue misses some groups due to a lack of a tank (for example missions done with pets as tanks have no room for a rogue due to fight mechanics), then try a bard, ranger, mage, shaman (these classes can molo easily in their spare lonely time), almost any group will welcome you.

Or try a plated tank, true caster, a priest. Just for a variety sake.

By the nature of personas, it really doesn't matter what the "native" class is. The recommendations are just like rolling a whole new character. If you wanna go meta, everyone knows the most popular classes are SK or Mag, for good reasons. If you want to be guaranteed a raid slot, then you play one of the OP ADPS classes Brd, Shm, Enc, Bst. If you're super cool and good looking irl and strong and nice then you play War or Cle or Wiz, obviously.

Druid.
You get ports and evac/succor. Super useful for everything when your not fighting as a rogue

This is a good point but we do have a ton of teleport things ...

The answer is none. Alt personalities have zero benefit for the swapped out toon.

Yeah, you can't use both at the same time, so it 100% doesn't matter. It's like saying what alt should I make, if I have a rogue already. If you could switch personas anywhere, then it would matter, but you can't, so just make whatever class you want to play. Personally, I just stick with alts, because I like to park them where I am camping and not jump through the hoops of switching between personas.