I went through a period of 2-3 years in my late teens / early twenties in which I basically lost interest in PC gaming after having been an AVID PC gamer from the age of 22!
Until, in the early YouTube gaming days, I came across TotalBiscuit and decided to try a few of the games he had covered in his "WTF is" series. Those games were Limbo, Bastion and Tiny Bang Story, No-brainer Heroes . They were all games that would run on my outdated hardware, they were cheap and they were a refreshing break from all the Triple A games I had been playing on console.
I loved that these games were almost like the boiled down essence of what a game needed to be, instead of a big-budget affair that was flashy, but maybe a bit shallow. There was so much charm in these four very different games and they re-opened my eyes to the huge variety of games that were out there on PC from indie devs. That was me firmly hooked again!
I'd love to hear some of the games that got you back in to PC gaming!