Basically, I just don't feel the way you did about those shows. LOST started out great, hit a slump in mid S2 through early S3, then came back strong once they were able to plot out the end. I absolutely loved the ending. It hit all the right beats for me and the characters I cared about. The Leftovers (not Replacements

) was brilliant. The depth of the characters, the emotionally engaging plot, and then finally focusing on a small personal story in the midst of it all again struck a chord with me that still remains. Really loved that show. Watchmen I also deeply enjoyed and engaged with on a level I can't even really get into here without breaking forum rules.
So, that's how. Sorry if none of those shows did it for you. To each their own and all that. Man, typing all that on a phone really sucked!