we hired a fishing boat while we were down there, and they took us with surf boards up to Ollie's point, which is a wave featured in the Endless Summer 2. That was awesome. It was a cool secluded lagoon, with an incredible point break, and no people around. You can't really drive to Ollie's, so that's why there are no crowds. Then we caught a bunch of Tuna on the way back to port. Playa Grande was sweet too, but more of a tourist spot.
Also, if your are open to destinations and just wanting a good surf trip, go to El Salavador. there are more breaks there than you could possibly fit into a trip, and the access to them is much easier than Costa Rica. There is a nice coastline hwy in El Salvador that gets you to all the breaks easily. And much fewer tourists, and less expensive (costa is not very cheap unless you drive into the boonies) . El Salvador is kind of like what costa rica was 15 years ago. Small friendly towns, cheap good food, cheap lodging, and INCREDIBLE surfing. here is a link to the sunzal surf co. http://www.sunzal.com/waves/index.php