Costa Rica golf courses are bunched together are two areas: Guanacaste and San Jose - with the exception of one course: Marriott Los Suenos. 
This is the definitive list of golf courses in Costa Rica as of Sept. 2010. 
1. Four Seasons (Guanacaste) One of the top 50 courses in the world
2. Reserva Conchal (Brasilito, Guanacaste)
3. Hacienda Pinilla (near Tamarindo, Guanacaste)
4. Los Delfines (near Tambor, Puntarenas)
5. Marriott Los Suenos (near Playa Herradura, Puntarenas)
6. Cariari (between Alajuela and San Jose)
7. Valle del Sol (Santa Ana, San Jose)
8. Costa Rica Country Club (Escazu, San Jose)
9. Los Reyes (La Guacima, Alajuela)
10. Monteran (San Pedro area of San Jose) 
11. San Buenas (Dominical, Puntarenas)

There are executive golf courses in Punta Islita and Tango Mar. There are several projects schedule to open in 2010 like Guanacaste Country (Liberia, Guanacaste), Cabo Caletas (Puntarenas).

Golf Tour Operators:There are several specialized golf tour operators like: Costa Rica Golf Adventures, Tee Times Costa Rica, and BJ Golf Tours.

A local specialized golf specialist will help you avoid "golf resorts' that are not really golf resorts.  When making reservations at a 'golf resort', please ask them if they actually have a golf course. There are some so called golf resorts that only have a driving range or are just thinking of adding a golf course.