Well, overall I liked the show. I had plenty of cool moments where Jack kicks butt and it was one of those shows where except for a few very select few, pretty much anything can happen to anyone. So you didn't necessarily know what was going to happen because there were twists, both in plot and because suddenly people you didn't expect to die were killed.
The storylines ranged from sorta meh to really interesting, but overall it always kept my interest, though the last couple of seasons it was really hard to do that.
The most annoying thing about the show, and I think most people will agree with me, were the side plots. I have to admit I didn't even realize until a long time into the show that the side plots were there to help fill in the time. Do we really want to watch Jack driving twenty minutes to get to the target? No, not really. And how can we have action when we're waiting for him to get to the action? Well, we'll just have his daughter Kim get into trouble and do something stupid.
So I could see how some people might not like it. But I did. I like the action well enough and the plots well enough and the suspense well enough to keep watching even through the dreadful moments, but for some, I guess they're unable to.