Soccer (FUTBOL) -- Ticos take their fútbol seriously. Costa Rican professional soccer is some of the best in Central America, and the national team, or Sele (selección nacional), qualified for the World Cup in 2002 and 2006, although they made early exits both times. The soccer season runs from September to June, with the finals spread out over several weeks in late June and early July.
You don't need to buy tickets in advance. Tickets generally run between $2 and $15 (£1-£7.50). It's worth paying a little extra for sombra numerado (reserved seats in the shade). This will protect you from both the sun and the more rowdy aficionados. Costa Rican soccer fans take the sport seriously, and several violent incidents, both inside and outside the stadiums, have marred the sport in recent years, so be careful. Other options include sombra (general admission in the shade), palco and palco numerado (general admission and reserved mezzanine), and sol general (general admission in full sun).
The main San José team is Saprissa (affectionately called El Monstruo, or "The Monster"). Saprissa's stadium is in Tibás (take any Tibás bus from Calle 2 and Av. 5). Games are often held on Sunday at 11am, but occasionally they are scheduled for Saturday afternoon or Wednesday evening. Check the local newspapers for game times and locations.