My vanquisher VIII (on Titan) , the only gun I legitimately lost sleep for lol. I played crucible for like 5 hours to get 100 marks,this was when you would get 2 marks for losing and 3 marks for winning. Keeping it as a symbol of how much of a pain in the ass it was for me to get. Granted at the time I wasn't the greatest pvp player nor am I the greatest now either.