I have played every Far Cry since the first. In my opinion FC5 is the worst. Boring setting. Far more mundane and repetitive than the others. The forced kidnappings were annoying. The ending was meh. I think FC6 was a refreshing change.

Personally Far Cry Blood Dragon is the best overall. The Vietnam DLC for FC5 is also excellent, even though short. FC4 is also great, and has a truly unique setting and was a lotnof fun with the gyro copter and Yeti. FC3 is good and fun, but it's overrated.

FC2 I think is the best FC in a spiritual sense. For all its flaws, it truly set out to implement a unique concept the other FC's have forgotten.... that is you set out to accomplish something and everything will go wrong. You were supposed to be frustrated and overthink things. The setting was cool, the story was effed up, and the buddy system was kinda neat.

All Far Cry's suffer from underdelivering on the story. So much potential with the villains, yet barely seen. People who brag about how cool Vaas is seem to forget you only see him like 3 times, he's gone by like mid-game, and he wasn't even the main villain.