I want Monthly nightfall raids. Imagine the VoG or Crota's End with burn modifiers, juggler, light switch, etc etc. If your team manages to beat the nightfall raid you have a much higher chance to get exotics. Maybe even gear that can only be obtain from the nightfall version of the raids. Nightfall raids would be the end-game of the end-game. Exclusive gear to get that can only be gotten from the nightfall raid, higher exotic drop chance, and it would be the difficulty that most max level people are looking for. Only a team of people who can communicate well and play well would be able to beat it.