Guides totally ruin games, in my ever-so-humble opinion. I haven't used a guide to finish a game in quite a few years. Having said that, I haven't actually played that many games in the last few years.

Everyone has their own unique way of playing a game, and that should be respected. Listening to people who tell you to 'do this' and then 'do that' isn't always the best thing to do. The idea of a game is for you to make your own decisions and then act on them. That's what makes games so much fun.