If you're still not convinced about buying a gaming PC, don't forget that it's not just an investment in gaming. PCs are also the best media players, with unfettered access to every kind of streaming service the internet has to offer. A PC is also good for editing videos, audio, and photos, as well as churning out term papers and job applications, so in theory, you'd be more productive with one than without.
Ah, who am I kidding? It's all about the games. Solitaire or Starcraft, Farmville or Far Cry, the PC is the ultimate gaming machine. Long may its reign continue.