There is no single "best" Dambulla tour — there is the right one for where you are sleeping and how many days you have. The list below is grouped by exactly that, from a guided visit of the caves if you are already in town to a long day trip from Colombo.
Everything here is booked through GetYourGuide, which means live availability, free cancellation on most options and reserve-now-pay-later on many. Prices are indicative "from" starting points in US dollars and change with the season — tap any card for the live price in your own currency. Entrance tickets to the Cave Temple, Sigiriya and the national parks are sometimes included and sometimes not; each listing spells it out.

