The best part of Mazatlan is definitely the beach. It's not white sand, but it's pretty, the water is warm, and the waves are not too big, so you can enjoy swimming.
Best Way To Get Around: Pulmonias (a golf cart on steroids) or by foot are the best way to get around. Buses are cheap, but their schedules are hard to understand. Remember that you can bargain with anyone, including pulmonias and taxi drivers.