I've seen clips of Grey's Anatomy, but I never watched it, not a hospital drama guy. I only watched House, because I kept seeing House & Wilson clips on YouTube, so I wanted to see more. I figured I'd watch maybe 5 episodes, get my House & Wilson fix, and bail. I ended up watching the entire series.
Lost, I didn't have any in Gilligan's Island, but serious, and with TXF-grade mysteriousness. I did love Fringe, found it on Netflix randomly back in the mid mid to late 20-10's and ended up watching the entire series.