I've use PGP and Truecrypt, and while there are overlaps in functionality, PGP brings more to the table, but PGP was designed with a lot more corporate use in mind, where TrueCrypt is really for the individual's encryption needs.
PGP offers file-level encryption, integration with email, self-decrypting archives, management keys and split keys. PGP also ships with a file secure delete, and other goodies.
Truecrypt does volume and virtual disk level encryption, but does it very quickly and easily.
If you have compliance regs, go with the commercial package.