Ok, this is my opinion on it. Normal villagers are plain and simple, kinda boring, yes they have some of the best designs, and one may be my favorite villager, but their personality is kinda bland, I don't suggest having two in a town. Peppy's, however, are my second favorite type behind snooty.
I'd suggest two peppy's, I have both Carmen and Chrissy in my town and they're amazing villagers! I got Carmen a while ago, probably around the first few months, and I have yet to find a peppy I like as much as I like her.
Merry: My opinions are a bit two sided, I did really like her since she was a starter in my town, but, her house was in a really bad place, and I really don't like the peppy cats, but she really won't disappoint.
Felicity: Again, same with Merry, she's decent.
Sprinkle: She's the only penguin that I really like, she's an adorable penguin who's simply one of the best peppies in my opinion.
I'm a bit biased, I'll admit, so I voted for Carmen.