I was on a Film Noir spree, and one movie featured this character; Dan Muldoon. He was really sarcastic and his voice sounded like a munchkin from the Wizard of Oz. At first, as a joke, I criticized his every action, placing phrases like "I hate you Muldoon" or "You suck, Muldoon" at 10 second intervals. I did genuinely dislike him, but I exaggerated it as a joke. However, towards the second half of the film, I began to have a strong appreciation for Muldoon, and by the end phrases like "I hate you, Muldoon" were replaced by "God bless you, you beautiful man".
Murphy from Silent Hill: Downpour traveled the same arc. At first, I didn't like him, but as the game went on and more of his history was revealed, I warmed up to him, and now I consider him to be one of the better protagonists in the series. He's not on the James Sunderland level, but thankfully he's no... *shudders* Henry Townshend.
Oh, and I felt the same about Andrew Ryan. It wasn't until later in the game that I recognized him as one of the most masterfully crafted "antagonists" in game history.