Same generation would be brilliant (X1 - PS4 and 360 - PS3). My experience would increase massively due to my mates who still play Destiny but on PS4. The Xboxers got bored and sold the game but still got mates playing on PS4. I didn't think it was possible but someone corrected me and said Final Fantasy does this and another game I can't remember. Pretty sure a generational cross over would be impossible though.