For those with bigger budgets, Interbus and Grayline run shuttles between top destinations starting at 22,300 CRC (40 USD).
Pros: very comfortable, include air conditioning, faster than regular buses, more direct.
Cons: way more expensive than regular buses.
Bus
Pros: the cheapest (short bus trips are around 2,000 CRC (3.5 USD), while longer will cost you closer to 5,500 CRC) and easiest way to get around Costa Rica, the public bus system runs frequently throughout the day, including the harder to reach areas.
Cons: you have to buy in advance as tickets sell out quickly, frequent schedule changes.
Pros: fast, doesn’t depend on road traffic, gets you even to remote locations.
Cons: very expensive, Nature Air – the only main airline in the country – has a quite the iffy safety record.
Pros: surprisingly affordable, flexible.
Cons: the roads in Costa Rica are in a bad condition, lots of traffic in San Jose.
Car rental with driver
Pros: reliable, drivers know the roads well and won't have any trouble navigating even if the roads are bad.
Cons: not as flexible, way more expensive.
Hitchhiking – isn’t common for long distance rides among the locals, but it’s more usual near the beach destinations or in remote places with less public transport.
Pros: free, you can use HitchWiki for hitchhiking info in the country.
Cons: won’t work for long distances.
Taxi
Pros: good for short distance rides (especially when it’s raining), comfortable.
Cons: expensive (especially for long trips).
Pros: often faster than by land, relatively inexpensive.
Cons: only an option for certain trips.