Baja california is one of the best places to see sea-life. Depending on the season different species can be spotted. One of the best places to explore is around La Paz, where you can get excursions to see sea lions, whales and whale sharks. The food is also excellent in la Paz.
Loreto is also a very nice area and on the west coast around Adolfo Lopez Mateos trips can be organised to see different types of whales depending on the season.
Cabos is a big touristic destination. San Jose is a more relaxed town with great restaurants and Cabo San Lucas is where you want to go partying.
Todos Santos is a “hippy” surfing town.