Most of mine do sooner or later. Phoebe was the most recent. I always get excited when they show up because Tipper sent me her pic in the mail the day after she visited, but nobody else has given me a pic that way yet
Teddy and Amelia like to surprise me the most but have also had Drago and Agnes do it once. I like it its really neat to see how much they like you to just do that.
Biskit, Rosie, Mira and Ankha seem to drop by the most. I think it might be because they live closest to me? That seems to be the pattern in my town, anyway. Biskit frequently misses our planned visits but drops by unannounced a lot. Usually when I'm trying to decorate, so it's kinda annoying.
I think most of my villagers have surprised visit me. I think especially Fang and Marshal. I've pretended not to be home so many times when Fang comes over because he does it SO frequently. I'm sorry but I'm trying to rearrange furtnitures! >u< I can't say no to Marshal though I end up just letting him hang out lol.
Not many, I don't spend much time inside. When I do, I'm decorating, so it gets a little annoying. I know Twiggy did not long before she left, and Bam has a few times.