Ditto on the 4-6 second kill, had that a few times as well. Had one double lunger that ran about 10yrs, face first into MYtree, then flopped over backwards. Not sure if my arrow killed it first, or the tree! [8D]
I've also had one like Greg/Mo described....dropped dead in her tracks (but I try to avoid that shot..LOL).
My favorite of all though, are the ones that don't even know they've been hit. They look around...wondering "what was that"....and 10-15 seconds later start to wobble. The first time it happened to me...I thought I missed!