I have recently booked an appartment for my parents in Lisbon through
Lisbonstay
They loved the city and liked very much the appartment :
+:
Very centrally located
Quite cheap
Charming decoration
Perfectly clean
Easy to check-in (the landlord was present for giving the keys at the convinced time)
No noise
-:
Not possible to pay directly on the Internet site (but via bank transfer or cash). I sent a cheque in euros but the bank ask for fees for the operation