Single Player or Multiplayer?

Most games today come with a multiplayer component; notably, 2007s Bioshock was a single player experience, focused solely on the story. However, this year’s Bioshock 2 has included a multiplayer component and the reason that games such as Halo 3 and Modern Warfare are still so popular years after their release.

But, for many gamers, myself included, the single player experience is paramount. While a game can provide hours and hours of fun with a strong multiplayer experience, there still is nothing that compares to taking the twists and turns off an excellently crafted single player story such as that of Half-Life or Deus Ex.

So, we want to know, what do you look for in a game? Do you purchase games because of their single player storyline or do you buy games for the multiplayer experience? What is more important to you?