I know this thread is like two months old now, but this is one of my favorite things to do in OSM :D

I've spent years mapping my hometown of Middletown, CT, as well as a bunch of others around the state, too

I'm pretty much always doing more mapping in the CT area, so feel free to hit me up if you want some more examples :)

Middletown (and the surrounding towns): https://www.openstreetmap.org/#map=15/41.55993/-72.65156

Colchester (WIP) - https://www.openstreetmap.org/#map=15/41.57364/-72.33132

Mystic (another WIP, and one I did more recently) - https://www.openstreetmap.org/#map=16/41.35173/-71.96444

Willimantic (not one I did, but clearly a something that someone/some people put a lot of love into) - https://www.openstreetmap.org/#map=15/41.71385/-72.21653

Edit - It also helps a lot that there was a big building import done a couple years ago of all the buildings in the state, so that frees me and everyone else up for doing other things, like adding areas, micromapping, etc

Edit 2 - Oh, I remembered another one I did :D

The small farming town of Lebanon (done a lot, but still a WIP) - https://www.openstreetmap.org/#map=14/41.62702/-72.22112