I totally recommend Helena and Tiago's apartment!
Localization is very very good, decoration is nice; the apartment is perfect for a single person and/or a couple. For work as well as for turistic purposes
Food recommendations of the maid were awesome: my favorite one - Casa Guedes - which is besides the apartment ;)
Coincidence or not, you will surely have a great moment at Helena's and Tiago (unless I did not meet them)