I don't know if it is worth a separate thread, but here is a quick list of characters that went down like a Boss vs. went down like a punk:
Went down Boss:
Joffrey - was practically throwing feces at everyone and they were taking it, right up until Queen of Thorns had enough of his crap.
Robb Stark - He did dump Frey's granddaughter for a hotter woman, and then brought his new tail to the Twins. He was rubbing Walder's face in it. Won every battle, and needed a huge betrayal to be taken out.
Renly - Kind of like the projected 300 game winner that tears his rotator cuff at 24, what could have been. Stannis needed to cheat to win.
Ygritte - took out about half of Castle Black before Olly got her.
Barristan - left a pile of bodies around him.
Hound - Lost one of the best fights of the whole show.
Hot wilding at Hardhomme - She was awesome.
Khal Drogo - no shame in dying defending your woman
Karl Tanner (psycho Crow at Craster's) - lost one of the best fights in the show
Stannis - took a lot of men down with him, including his own.
Jon Snow
Went down like a punk:
Tywin - taking a dump after banging your son's leftovers? Not much dignity there.
Roose - I expected a better exit
Lysa Arryn - One of the worst players in the game.
Doran Martell and Areo Hotah - if you lose to the Sand Snakes, by definition you went down like a punk.
Eddard - Jackass deserved to die. Everyone is trying to help him, including Renly who could have handed him the crown. Instead he walks into the Throne Room with a piece of paper. Nice work.
Robert Baratheon - best warrior in Westeros becomes a drunken slob and gets stuck by a pig.
Oberyn - That is why you don't run up the score when you are winning.