Ouro Preto - be ready to walk on cobblestones and hills... not a great combination for some, but it is absolutely beautiful if you're up to the task.
We really enjoyed our time in Ouro Preto - we walked around holding hands and no one gave us a second look, which you might think strange for a smaller, older 'countryside' town, but we always felt safe and welcome. There is only a little nightlife in Ouro Preto though, and that sort of includes restaurants. We walked around for an hour about 930 pm and came across 5-6 restaurants (some looked delicious though) but they were few and far between so I'd recommend having some idea or planning during the day when there's a lot more happening because a lot of everything shuts down after dark. There were two bars right across from each other just off of Praca Tiradentes though, and they were full and spilling out into the street, so there's always that. All in all, a beautiful romantic historic town that we had a great time in!