San Francisco is one of my favorite places to go because no matter how many times you visit, there's always something new to do or see or EAT. I've found the best way to book is through Expedia with a flight/hotel package. Between me and my BFF, we spent about $350 on a roundtrip flight and two nights of hotel in a really central area. The flight times gave us three WHOLE days to wander. We also got a three day Muni passport which gave us unlimited bus, street car, and cable car rides which covered virtually ALL of our transportation. We purchased two tours- one city, and one boat. One of my favorite things to do in a big city is take a Hop On Hop Off tour. Things look different on a double decker bus! It's also a great, easy way to get around and there are so many different companies that offer these tours. We got a 2 for 1 deal!