I find it really hard to pick a favorite in this group of companions.
Mako is awesome both in the fact she is the best partner for questing for my tank. Add to that her personality and abilities make her a nice match for my BH.
Blizz is to good to be true he is the cutest thing. He makes me laugh and is a good person to have on my ship. I have yet to see anyone not like Blizz may be our best companion.
Gault is funny and can do some great damage when loaded up. He is a bit to lets say posh for my perfect fit but I am glad we have him on our ship.
Torian is a bit dull and one dimensional but he is driven and fills the "apprentice" roll that force users get.
skadge I do not have allot of time with so far but he is replaceable. I am not a big fan of his and would rather he not be on my ship, but he is a tool that I can use as operation get behind dummy.