I'm gun shy.

Lonesome Dove I believe to be the greatest production of all time.... of anything ever put on film/digital it's tops. Some others are close but Lonesome Dove, for me, is KING. It's actually proof that perfection can be achieved.
And for that reason... I'm VERY hesitant to watch any sequel while admitting that it's possible some of them are very, very good.
And Lonesome Dove isn't the only movie I treat that way. Several other movies I consider classics have had sequels, or remakes, and I will very seldom watch them. I have done so, a very few times, and nearly always been disappointed.
Kind of related - a list of the movies I've seen the most times - not in any order OR ranked by how much I liked them... this is just what comes to mind:
Lonesome Dove
Butch Cassidy and the Sundance Kid
Casablanca
The Wizard of Oz
The Dish
Local Hero
Citizen Kane
The Godfather (Godfather II is close... Godfather III I saw once)
E.T.
It's A Wonderful Life
To Kill A Mockingbird
Just a guess but I'd say of those above It's A Wonderful Life would be "most" for me.
I'm sure there are other that should be in that list - but next: Somewhat close but not as much as the above -
Stagecoach
The Graduate
12 Angry Men
Forest Gump
Unforgiven
Raiders Of The Lost Ark
Jaws
Treasure of the Sierra Madre
Shane
Dances With Wolves
No Country For Old Men
Seen those many, many times each. Some I like as much as my first list BUT... no opportunity to see them as often.
Just to end this... I'm not good at 'remembering' loved movies 'off the cuff'.... so I'm POSITIVE I left out some I have seen just as much as those I listed. - JamesJM