My issue with the Cell saga is the damn Cell Games. That ruined it for me. Couldn't stand that plot device. From Trunks arrival till Cell becomes perfect was great, but the entire concept of Cell kinda irks me.
Also Dr Gero was very underutilized. A creepy old man that kidnaps teenagers should have gotten more screen time and should have been a bigger threat. He's the real villian of the saga.
Well, Dr Gero was originally going to be the big bad, but toriyama's editors didn't like androids being an old man and a clown, so 17, 18, and 16 were introduced. The editors didn't like the idea of a couple of teenagers being threats, so Cell was created.