I'm actually going to have to dispute that just roaming around is the most fun to have in this game.
I come from a school of gaming where the best experience I can possibly have is a good story, told well and paced to perfection. Open world games are largely a "make your own story" type of affair, but as brilliant as the random interactions with other people and the environment are in Read Dead Redemption, I still feel like the actual missions outshine everything else.
I mean yeah, I probably have split my time something like 60/40 between missions and everything else respectively, but the way everyone's going on about the amount of stuff there is to do in this game, you'd think it would be 60/40 in favour of the everything else side. I don't think there is actually as much to do here as people say there is, or maybe that's a flaw with my own creativity in playing the game.
Either way, I'm just playing devil's advocate and RDR is the most fun I've had playing a video game since GTA4 came out. GTA4 was the only open world game that I could dick about in for 12 hours at a time and not get bored ONCE, whereas with this game the most I've managed is a 6 hour sitting with a few bored spots, but for some reason it doesn't seem to matter.
This game is far more than the sum of its parts to me, and I suppose that's the point, and it's one of the finest pieces of art to grace this generation of games thus far.
Gets a solid 9/10 from me.