I went to Cabo about a year and a half ago. There's still plenty of shrimp, and fresh tuna is averywhere.
The little sidewalk cafes in town are great and cheap.
A little more touristy, but fun, check out The Office right on the beach.
Also, Mi Casa for authentic mexican, make sure you go the the original one across from the main square in town.
There's also Samy Hagar's restaraunt/bar, The Cabo Wabo Cantina.
We got lucky, Sammy was in town and we got a free show. Try the Cabo Wabo Tequila. I'm not much of a tequila drinker, but it was pretty tastey. The food is good too.
We stumbled on a restaraunt called the Sea Queen right in town. The food was amazing. It was more a fine dining experience, and a bit pricey, but well worth it. Check it out:
http://www.loscabosguide.com/restaurantreviews/seaqueen.htm
Oh, and if you like Ceasar salad, many of the restaraunts will bring the ingredients to your table and mix it up right in front of you.
Take a boat ride out to Lands End where the arch is at sunset, it's absolutely beautiful. They have dinner cruises, party cruises or glass bottom boats to take you out there. I think you can even rent a kayak and paddle out there.
There is also Lover's Beach out there. Water taxis run regularly to the beach from the harbor.
We didin't do any day time trips, (we were on our honeymoon), but there are hiking or ATV trips to the desert and scuba diving. Boat trips and fising trips out into the Pacific. They should have info at your hotel about these trips.
Have fun!!!