As has been said before their are many likeable admirable or memorable characters but my favourites so far (Riftwar, Serpent War, Krondor the Betrayal, Conclave of Shadows and Flight of the Nighthawks) are Baru and Martin.
There is something particularly appealing about these two (quite similar in many regards characters) both are taciturn honour bound men of great skill but without any special powers and a great deal of good sense.
I wasn't entirely happy with the old Martin in the The King's Buccaneer, I think he became something of a doppleganger of his father with his oftentimes severe nature that and never getting over the loss of his wife.
Still killing off Briana in that fashion was a great way to get me incredibly pissed off at the villains of the piece.