SOTC wasn't a surprise hit, I expected it to do better given the internet hype surrounding it.
For the same reason I expected Far Cry 5 to sell like shit, Ubisoft has accrued a bad reputation and I saw the internet saying it was another Ubisoft open world game and didn't change the formula so they weren't buying it. Sold record amounts for Ubisoft and nearly as well as GTA 4 at release.
MHW did incredibly well and I did not expect it either, but I never had any idea of what it would sell like.
God of War sold incredibly well, post SOTC I thought the internet hype wouldn't become sales, early reports this year indicated preorders were low and God of War as a series had drastically declined in popularity this gen, and where critics loved the stories in the original games at their time of release they were harping on how one note it was this gen. So I was surprised to see God of War do so well, but on the other hand the direction is a lot more modern gamer friendly in that the story is in your face and characters are more sympathetic which I could see from earlier trailers so in that way I wasn't all that surprised with the sales.
I voted Far cry 5.