I have used TrueCrypt for years without any problems. I trust it to be impossible to crack, though depending on the length of your password.
I am using Bestcrypt (Jetico) for several years now - excellent software. It is able for file encryption, public key enc., volume encryption (whole disk) and can create containers. All features work with W8. If you need to transparently encrypt e-mails, I would recommend PGP Desktop (Symantec) (works with outlook 2013 32bit). You can use all its features with W8 except the whole disk encryption.