I REALLY CAN'T believe you people ACTUALLY USE Martyrdom. That perk is a joke and such a cheap joke at that. Not only is there a 1:100 chance of actually killing someone with it, but when you kill someone with it, they are either n00bs or trapped and either way you look at it, they are EXTREMELY cheap kills and prove nothing at all.
They are only fun when you are playing hardcore and there are a bunch of team mates around.
Deep penetration, extreme conditioning, and dead silence are the top three third spot perks.