→ ring a bell
CSI. I watched it for a good while and then I stopped for a bit. When I tried to watch it again they the cast had almost completely changed and it just wasn't the same show that I used to watch anymore. I don't think I'll ever try going back and watching it again.
Supernatural. I enjoyed what I have watched of this show, but starting season three or four it was already getting hard to watch with the repetitiveness of the drama and so forth. Maybe one day I can give this show a shot again but I don't see it happening any time soon.
I know there are more of 'em but those are the two I can think of off the top of my head. I haven't watched Criminal Minds in a while but I am definitely planning on catching up so it doesn't count.