Honesty like saying you're gonna put up contest winners house banners then doing it
Sacrifice, because it lets me get back into the action quickly
2nd only to compassion, which lets me get my companions back into the action more quickly too.
I like all the ones that can be used in Felucca, have a use in PvP, and in general gameplay.
I'm not such a fan when a Virtue is really only for a particular class.
I think gaining the Virtues to become an Avatar is a cool part of the game, and any character with all 8 Virtues should potentially be open to an additional gain/reward.
Sacrifice. Brilliant.
Compassion. Great.
Spirituality. Fine.
Honesty - Cool.
Justice - Nice.
Valor - Decent.
Honour - Very hard for Mages to get. Based very much around warriors. Useful Benefit.
Humility - Can be obtained by anyone, but only useful to Tamers.