I am 98.?% complete Red Dead Redemption. Not sure what I haven't done yet, and I don't really feel like combing through the stats to figure it out right now... but I will find figure it out!
My friend just finished playing this and got 100% completion.
The last 2% had something to do with knifing a bunch of bears and then killing a jaguar.
I was hoping that once he killed the jaguar that there would still be 0.5% left than involved riding a bear and killing a pterodactyl, but I was disappointed.