Oitavos is the obvious answer; it's not as good as the rankings make it out to be and unfortunately the owner thinks he is both a golf architect and a greenkeeper, so it isn't achieving all it should, but there are some wonderful holes, it's a beautiful spot and it has everything you'd want from holiday golf. Drew Rogers, who designed the course on behalf of Hills/Forrest, did an excellent job - I know there's a bunch of things he'd like to change and hope he gets chance to do so one day.
I second Bill's praise for Lisbon. A wonderful city, one of the nicest in Europe. And the food is some of the best you will find anywhere. Especially if you like seafood.