If you are a traveler who wants to do and see lots of things, don´t think twice about The London Pass
The London Pass is a card for tourists (that also exists in other cities) where for x number of days (depending on which option you choose) you can have unlimited Access to public transportation and free entry to a lot of places, as well as discounts for other activities including movies, theater or musicals. You can find a list of all the attractions that are included, as well as prices on this website
My experience with the pass was really great and if you are going to really see the city, its definitely worth the Price. Although London has a lot of free things to offer in terms of museums, etc, you always have to use public transport. If you want to go off the beaten path and maybe take a tour of Standford Bridge, tour the Wimbledon Museum, cross the Thames on a boat, visit Westminster Abbey, climb up the Tower of London, gain entrance to a number of cathedrals, churches and museums like the Tate Modern, or loads of other things, then you should take advantage of this card. The only thing missing is free entrance to the London Eye, the famous ferris wheel – however they do give you a discount on the ticket.
At the end of the trip I did the math and it wound up being a pretty good deal. Depending on what you like to do on your trips it might be worth it, or maybe not. But if you are a traveler who wants to do and see lots of things, don´t think twice about it. If you have stayed at Berlin, Paris, Madrid or any other city with this tourist card, tell us your experience with it!