Yeah but whilst Little finger was sneaky and manipulated everyone he wasn't cruel for the sake of being cruel and eventhough Little finger was annoying you had to admire what he accomplished without ever getting his hands dirty or arousing any suspicion. Basically I just didn't hate him as much as I hated Ramsay and Joffery so his death wasn't as satisfying.
Also, iirc the only person who he actually killed himself was Lysa and she was a rotten old **** herself anyway and deserved to be ****ed out the moon door
