PC's are more costly. If you build them yourself, like me, then I'd say that a decent rig costs about $1200. (And that's just the tower) And you'll probably upgrade every 2-3 years. Which is about the same amount of time in which a console generation lasts. A console costs ~$200-$500, a big savings.
PC gaming is for those that can make the game time count. Consoles are much better suited for those that are "casual" gamers.
Then there are the games themselves. PC exclusivity seems to be a rarity nowadays. Seems that developers go console side first, and if the game succeeds, a PC port is started. (Mass Effect, Assassin's Creed). The only real games made for PC are those that simply are not possible on consoles. Mostly RTS and some MMO's (Command and Conquer, WoW).
Its about games you like to play and cost. Choose the one that gives you the most of what you want, and still stays inside the budget.
A personal aside:
For me, the thrill of making a new creation (my gaming rig) every couple years is exciting and a special ritual for me. Including my own personal touches; such as case lighting, water-cooling and custom paint. I'm probably going to build my masterpiece this Christmas with money I've been saving.
Its this process that will always keep me a PC gamer at heart.