After years of going back and forth between owners, legal woes and skirmishes with the U. S. government, PGP now is the most popular encryption suite in the world. This is a well-thought-out suite of encryption tools that work transparently with just about everything they need to, and they offer the expected superb data protection on many levels.
I have had PGP whole disk encryption on my university Dell laptop since I got it and I really have not treated that poor little PC as nicely as I should have. There have been lots of crashes and ungraceful shutdowns. I used to worry that I would never see my data again (pray for a current backup) due to corruption of the encryption. I never needed to worry. There never has been a hiccup in the nearly three years I've had the computer.
In today's environment, laptops get stolen, data gets hijacked and other nasty things can happen. I really like the peace of mind PGP gives me, have for years, and that is why it has been and is one of my personal favorites. And its many benefits, from many levels of protection to strong functionality, is why PGP made it to this list.