The worst bite I've ever suffered was to Petey's (one of my Meyer's) beak.
I can tell you I knew it was going to happen before it did. All happy that I had managed to successfully get Petey to step up onto my finger consistently for a week rewarding the good behavior with some of his favorite treats, that one day...I didn't do anything different, but in his body language I saw one fraction of a second before he nailed me that it was going to happen.
He got my right index finger was was not letting go. You know when people tell you to push into the bite versus pulling out of the bite to get the bird to let go (I think since they are surprised this happens)..yeah well it didn't work with Petey, he just got to dig into deeper. I'm not sure how, but I was quite calm through the whole ordeal, no screaming, to shaking the hand, no nothing but being puzzled as to how I was going to get this bird off of me. I calmly walked around my apartment in search of a small towel to put over him so I could try to pry him off keeping my other fingers intact while he was really going at it on my finger. I finally found a towel, pried him off and gently put him back in his cage (he was still pretty riled up, didn't want more "accidents"). He did calm down after 5 minutes or so.
But man did it hurt. My finger was swollen for a few days (if not a whole week) after that.
I also have a lovebird, have been around a few of them before as well, and trust me, none of their bites can compare to what Petey did. If I remained calm during that, it's quite easy to not overreact with a Lovebird