I always loved skyscrapers and I would love Lisbon to have a skyscrapers area some day. I think skyscrapers give that future look to a city, but I only like them when they are all together in a certain area, not spread around the city.
Although compared to some skyscrapers around the world the Skyscrapers projects for Lisbon are really tiny, some of them look really interesting.

You can see a list of proposals here and a list of rejected projects here.