I'd probably have to say that my favorite Lion is Mott, though his grasp of that position has been slipping lately since I've had him for a while. I had him as a resident of one of my towns for a while, then when he decided he wanted to move out I allowed him to, but came to regret it. After that, I came to the conclusion that I wanted to reacquire him someday and began planning a new town that I could adopt him into, which would in time become my circus/magic show town. It took a little over a year from the time he left that one town, but I eventually got another copy of New Leaf to make that circus/magic show town and figured Mott would be one of the stars, since circuses famously tend to have lions. I like his design overall, the Jock personality works for him, and while the interior design of his house leaves a bit to be desired, I still like him a lot.
My second favorite, and who I was initially going to say was my current favorite since I plan to adopt him in New Horizons, is Bud. I like unique villager designs, so I'm a fan of the sunglasses and think he'd be a great resident in New Horizons since it's on an island. The interior design of his house might be a bit redundant though.
Honorable mentions to Aziz, Leopold, and Lionel. I like both Leopold and Lionel's designs, and they both have the great Smug personality. Haven't had either of them in a town yet, but would like to in the future. I guess I prefer Leopold a little bit more because, while Lionel has a pretty great interior design of his house, I don't really like the unnecessary cheeks Lionel has. As for Aziz, I've liked his look since I saw it in the Player's Guide for the GameCube game back in the day, but I've never had him either. I wish he would have returned in the Welcome Amiibo update. His blue mane makes for a good look and he stands out in a good way.
