Next time I will stay in Cascais longer and day trip to Lisbon.
I had been worried reading that Cascais was over-developed and resorty. Well, it is not tacky at all and is very upscale. Think Capri, Cannes or Mykonos. Lots of tourists, but there is a reason for that.
Charming old town, with cobblestone winding streets to get lost in. Old buildings, outdoor restaurants around open squares, lots of beaches, a marina, museums,,,, So what if on the way to town you pass a macdonalds? and, there are some designer boutiques on the outskirts.
Overall, the town retains its charm, and doesnt have loads of tacky cheap t-shirt and postcard stores (has some, not overrun with them).
Great base to visit Sintra as well.