CSI is the only of the current franchises I ever regularly watched, even though I haven't for decades, I'll have to say that.
I gave up on it around season 4. The problem with franchises is that they get repetitive. I gave up on NCIS a long time ago as well. Probably the only franchises that I continue to watch are Doctor Who and Star Trek on TV/Streaming. Otherwise, horror franchises tend to keep things going for cinema. Check out the Conjuring.