The most expensive game I've ever bought is a tie between Dead or Alive 5 and Mass Effect 3 limited editions at $80 each. Dead or Alive probably my favorite game series from my childhood. My dad and I spent hours playing DOA1 and DOA2. I miss those days and thought that regardless of the quality of the game or the bonuses included, they deserved more money for the happiness they brought me over the years.
Mass Effect has become my Star Wars. I know they're not the most perfect games ever. I know Mass Effect 2 has become streamlined, and I don't care. Sure, they have disappointed me from time to time, but the characters, the world, and the feel are astounding to me.