Went to Rome for the first time last week and we thoroughly enjoyed it, only 3 nights and way too short to see everything and we're not big on sightseeing, will want to go again.
This Summer is Portugal again with the inlaws, we bailed last year, same place, same villa as every year but MiLs 70th so have to go this year....that'll be quite a few times to Portugal over the years.
I'm actually jealous of those going to Germany I've been looking longingly at something along the lines of a two part fortnight there. Maybe a week doing the mountains and a week doing cities, 1 to 2 nights in each.