I've seen on animal crossing wiki sites that they're supposedly also known as 'sweet' or 'sweetie' type villagers! Sounds better than 'normal' but I think it's the translation from Japanese.. 'ordinary' would've been a better choice but I feel like they deserve better than that.
Most of the personalities in New Leaf are nonexistent anyway. Back in the gc version and WW, Snooty and Cranky were actually snooty and cranky. Their villager type wasn't just for names. They could be really nasty.
I always gravitated towards the lazy and normal type in those two games, because they just weren't jerks lol.
I like peoples' suggestions of modest, kind or humble best. They're positive words that reflect their sweetness.
I'd love a nerd type, but I think they'd need to have a bit more spunk than the normals. If anything the normals seem creative or artsy, rather than nerdy specifically.