There are similiar threads for GTA IV and V & nothing is perfect so I figured one should be made for RDR too.
Overall it was an outstanding story and John Marston is one of the best video game protagonists ever but nothing is perfect.
Personally I would have killed Bill Williamson in the Act 1 ending and given Javier Escuella more screentime in the Mexico arc (dude appears for the first time in the mission he dies, wtf).
I would also shorten the Mexico revolution plot as it felt way too dragged out and repetitive & apart from Ricketts the characters were meh. Act 1 and Act 3 are much better in every way.
Also instead of Undead Nightmare a prequel DLC about Marston's time in the gang would have been better imho, it would have fleshed out the gang more + Abigail too.