Lisbon is really a walking city. You stroll down broad avenues and past upscale stores, markets, and restaurants. But like any European capital city you may want to cover more ground a little more quickly at times. There are lots of choices: the metro, buses, and trains. The most fun are the funiculars, the Santa Justa elevator, and the ancient trolley.
The trolley is a great way to see a lot of the city as you travel to the attraction of your choice. The herky jerky ride is fun and it makes you feel alive and happy to be traveling in such a beautiful cosmopolitan city.