I myself use Truecrypt. What i do is i create a encrypted volume (A folder which is then encrypted and turned into a non-open-able file until its decrypted) and i use Serpent-Twofish-AES.

It first encrypts with AES (256BIT) then with Twofish (256BIT) then with Serpent (256BIT), and i use SHA-512 as the Hash Algorithm. Then use a 25+ (Mines more) Long password to avoid brute-force. (Passwords like "Today.Me.And.My.Mom.Played.COD.7.And.I.Beat.Her" are good, whos going to guess that? And what password list will hold that?)

Also, when it comes to encrypting an actual Hard Drive with *Nix i reccomend LUKS. I know its available for Arch, i have never tried it on anything else. With LUKS you can do a mixture of i think the same 3 encryptions, and you choose what BIT you want.