Trave sama
I prefer Momo solely because I felt he had more personality than Pabu
lol, that is true.
Time for a confession... I honestly found Momo really annoying the first time I watched AtLA. Like, I thought he was the most silly, useless addition to the show. They already had Appa for an animal companion! What did Aang need Momo for?
Momo has grown on me since then, and I like him now, but in comparison, Pabu has never been annoying, he's just cute. Then again, cute kind of is all he is. Like you said, he has no personality.
So I pick Appa, as a happy medium between the two. He has personality without being annoying. xD