I've played through them all and they are good games just not at full price. The gun play is fun and stories entertaining enough but the gameplay can be a little repetitive on FC3, 4, 5 and New Dawn. Blood Dragon is the same but gets a pass because its short and hilarious!
Still there is fun to be had if you like wandering around, finding interesting secrets and locations and shooting things. FC4 was actually my favourite just because I liked the location.