I've been contemplating building a gaming PC for quite some time, but have decided to finally take the plunge - albeit at a low level. Since I still intend to be purchasing and playing on consoles primarily, with PC gaming mainly just so I can play some cooperative games with my friends, I don't need one with the greatest of specification. I just want to be able to run games at a comfortable level at 720P resolution on my 42" television. What sort of processor and graphics should I look to? How cheap can I build one to meet this demand?