When you walk around Fisherman's Wharf, you'll see people, lots of people. People with nothing better to do than browse through cheap souvenier shops that all carry the same merchandise. People dressed in tank tops and shorts and shivering and whining because they didn't read ahead that it is, indeed, winter here in San Francisco. People purchasing clam chowder from "authentic" street vendors and eating at chain restaurants like The Rainforest Cafe and In 'N Out.
The waterfront is really nice and on a clear day you can see the Golden Gate bridge in full and the beautiful hills of Marin county.
Fisherman's Wharf has served as a docking place for fishing boats since before the Gold Rush. The fishing boats still operate today, and the Wharf air is thick with the smell of fish just out of the Bay. While you can take a tour of the Bay on a boat, you can also watch fishermen bring in their goods.
Now let's move down the way a little and see another major attraction in San Francisco: Pier 39. If ever there was a tourist trap, it is here, my friends. You can do anything from getting a spray-on tattoo to renting a bike to ride across the Golden Gate Bridge (which we've done - very fun). You can see the sea lions and smell their...perfume from blocks away. You can even get sourdough bread and watch the bakers at work. And you can taste pretend San Francisco cuisine.