Places to go:
The nowhere bar for ladies night (I know you said its you anniversary, but on ladies night, women drink for free)
Senor Frogs is a great time but you gotta go late
Lover's beach is cool, but not great. (DO NOT swim on the pacific side at lovers beach! I can't stress this enough)
To be honest, the diving there was lack luster. I'd save my money and do something else. The Fishing is great though. I can't recommend a particular charter, but what I did was go to the docks early before they left and looked for a boat that was partially full and asked if i could join. I got to go for a full day for $150!
The office is pretty cool (little bar on the beach)
Also when you get there (if you are a beer drinker) go to the corona brewery on the first day you get there, buy a case. You can get trade the empties in for full beers for about $5.
There's another place that I am blanking out on the name of, but its a restuarant where basically, it costs $9.99 and you can choose your meal. I got steak and lobster tail served with veggies, potato, etc. Sounds shady I know, but honestly the food was excellent and the wine selection was outstanding. It was very busy so make reservations though.
Also, if you have the time, grin and bear it through a time share presentation (they usually provide breakfast and booze). They usually offer a promo at the end. My fiance and I got a free whale watching trip, and dinner for two at a great little resturant.
I loved Cabo when I was there. Been a few years though. We stayed at the Marina Fiesta resort. At least thats what I think it was called.