10. Horse Armour - The Elder Scrolls IV: Oblivion
An early example of DLC burning its fans, Oblivion's infamous Horse Armour debuted in 2006, when DLC and online content was still very much a new thing - and it may well have opened the floodgates for what was to come. For just $2.50, players could drape their mount in some gaudy golden armour as they rode across the verdant land of Cyrodiil.
In the current gaming climate, $2.50 for a cosmetic item doesn't seem like much at all - in fact, players are known to spend hundreds on such things - but back in 2006 this felt like a massive insult. What didn't help was that Oblivion was a single player experience, so the only people to show your purchase off to were stiff-faced NPCs who couldn't care less rather than obnoxious other players, who also probably couldn't care less.
Acknowledging their error, Bethesda acknowledged their misstep on April Fools' Day 3 years later, where they did a sale on Oblivion content - everything was half price except the Horse Armour, which they doubled. The company had the worst up their sleeve, however, and may well be making another appearance on this list.