I have recent got back into playing S3 and Dragon Valley is quite a good town in my opinion. I appreciate that the designers left a lot of empty lots so players could set down lots from expansions and the Store, which I took liberal advantage of. There's also a fair bit of ocean area to lay down diving spots and a hidden island or two. It's made a good world to set my Silmarils (sims based on LotR RP) in.
I want to try Midnight Hollow, even if it is dark. I like Moonlight Falls and I would like to see of Midnight Hollow is an even spookier sibling of it.
I have fond memories of Lunar Lakes, Appaloosa Plains, Twinbrook, and good old Sunset Valley, though the latter is more because it's the homeworld of Mort and Bella, who I came to adore in S3.