No movie could top this book IMO, but I really do find both films to be good and I appreciate them both as an artists interpretation and nothing more.
Having lived with an alcoholic, I found the family dynamics in Kubrick's version to be on a different timeline of the same problem as those in the mini series. In the mini series it reminded me of the beginning, or the end, of a relationship poisoned and unable to survive an alcoholic while Kubrick's version reminded me of the middle (Duvall didn't portray much hope in the sense of ever actually striking out on her own), or having just given up. Some (but not all, of course) spouses of alcoholics develop a very worn and tired appearance. I think Kubrick was looking for this, as well as her exhaustion on set to further portray the idea of a wife who's lived with this so long that she's been beat down by it.
I personally think Danny Lloyd was about the cutest thing on the planet, and even if book/mini-series Danny was much more outgoing, talkative and willing to talk about his abilities, Kubrick's Danny struck a core with me as fitting into the typical alcoholic family; the role as the child, by being quiet, slightly secretive, and somewhat withdrawn. I fit that mold as a kid myself, and I thought his performance was pretty on par with his alleged life (even if he didn't realize at the time that his performance was on par!)
Only my opinions, of course. Again, I prefer the book hands down, but I do appreciate both films as works of art.
Cheers