Alright, the thread title came out bit since I couldn't think of more fitting name for the thread. In short, most of us (hopefully) have purchased game for odd reason, haven't played a popular gaming series, dislike a game series that's popular among most or like a game or game series that's considered awful by most, just examples.
I personally have two that come in my mind.
I got into Final Fantasy games because of music.This is the only "odd" way of me buying a game I can think of, The game had already been out for few years and I was visiting my cousin and saw him play the game for a while, he triggered a boss fight (Think it was first battle with Reno) and I was immediately sold. Now that I look back, the movies I loved as kid such as Star Wars and Jurassic Park had quite memorable music as well. I bought FFVII as my first FF game and fell in love with the series immediately, English isn't my first language and I was quite young back then, so I pretty much learned English by looking up unknown words to me from dictionary. Nowadays I work with music everyday and compose it myself as well. It isn't far from saying that Nobuo Uematsu's brilliant soundtracks got me into music, if not that, the man is massive inspiration to my music and the reason I got so into it in the first place.
I haven't played a single Zelda game but...
..I still have 3 Zelda OSTs. Another music related, sorry. I've never played a minute of Zelda game, but I love the soundtracks in the game. Some day I'll force myself to buy one of the Nintendo gaming systems and games on the platform. I've been planning to do this quite a while, the ones in N64 look the most interesting to me. Gerudo Valley was the first song I absolutely got hooked to.