The best tours of Lisbon are offered by Lisboasightseeing, Rua Pascoal de Melo 3 (tel. 21/967-08-65-36; www.lisboasightseeing.com). The half-day tour of Lisbon, costing 34€, is the most popular, taking in the highlights of the Alfama and visiting the major monuments, including Jerónimos Monastery and other attractions of Belém. It even goes over the bridge spanning the Tagus, for a panoramic view. Both morning and afternoon tours leave daily throughout the year.
The most recommended tour of the environs of Lisbon is a daily full-day tour costing 82€ and taking in all the highlights, concentrating on Sintra, Cascais, and Estoril. There's also a full-day (and jampacked) tour offered daily of the highlights north of Lisbon -- Fátima, Batalha, Nazaré, and Óbidos. This tour costs 86€. Many other tours are offered that might be more suited for your desires -- check with the agency for the current agenda.
If you want a more personalized tour, check out the offerings of Inside Lisbon Tours, Avenida Forças Armadas 95 (tel. 96/841-26-12; www.insidelisbon.com). Patrons are transported around in small vans and then taken on different walking tours through the most colorful and historical zones of Lisbon. A popular summer addition is a twice-weekly pub crawl. The tours are given in English and enough free time is provided to explore each district in some depth. Only eight people at a time are taken on a tour. The labyrinths of the Alfama are the most desirable and intriguing of the tours.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.