Another is Talos. Really, that cute little man with his hilarious "just let me at them!" call saved SI gameplay for me. Was kind of bored and had to force myself to continue leveling.
Talos LOL not only does that crack me up every time he says it, he's fun to troll, too (all those lost affection points for purposefully choosing the worst possible bloodthirsty DS responses when he's with my SI are made up for with warehouses full of cultural artifacts).
My BH just got Gault. As of right now he ranks right up there at the top of my fun-non-LI-companion list because of the snarky attitude