Shows that started off meh but got good......I'd go with Person of Interest with Jim Caviezel. I watched the pilot back in 2011 and didn't watch it again because it appeared to be the same, major-network, procedural, plot-of-the-week crap. And it really was, for most of the first season. Years later my sister asked me had I watched it because she thought I'd like it. She knows me pretty well so I gave it another try on Netflix, at the time. It did develop an over-arching plot that became better and better over time. But s1 was still quite meh.