My all time favorite smug is definitely Beardo! The personality fits so well in making him seem like a dorky, middle-aged guy desperately trying to fit in with the world around him. I've had many smugs and I swear there's just something about his dialogue that gives off that "I just want people to think I'm cool" vibe even if it's all the same between smug villagers.
A close second is Eugene, because who can say no to a cute greaser koala?
My all time favourite is Lionel, but of the ones you listed I really like Kyle, Shep and Pietro. However Kyle's house is the worst (I actually kicked him out of my town because it looked so bad from the outside) so think that over carefully. I think if I were you I'd go with Shep
I really like Rodney. He was an unexpected move in (right next to my campsite, even) and I was prepared to let him go, but he won me over. He's this chubby little nerdy hamster who has an arcade/ gameroom style house and talks about how he wishes anime music were more popular.