Depends if you're talking about dangerous to a population over time, or dangerous to an individual.
Earthquakes have probably killed the most historically but the really bad ones are so few and far between, you've got a good chance of living in a "high risk" zone and getting through your entire life without experiencing one.
If you do get caught in a bad one, there's nothing you can do. They can come without warning, and there's not much you can do if you've suddently got a building collapsing on you.
Destructive volcanoes are similar in terms of frequency, but are more localized and prediction is getting better and better so you've got a decent chance of being evacuated.
Hurricanes are probably the most dangerous to an individual. Not necessarily in terms of risk to life, but if you live in a high risk area, you're guaranteed to be effected by them.
Tsunamis again are theoretically survivable in most scenarios as warnings are getting better since the one in 2004, although obviously you're completely fucked if you're somewhere flat with no high ground to run to.