Rogue/Priest is a staple for 2s, don't feel any other Disc Priest comp is better. In a short game Rogue is amazing, in a longer game Rogue just gets stronger, can pull off some filthy resets too.
3s RMP is good, but RMD is just better. Plus you really have to know very well who you play with, you could all be 2400 players but you'll play as though you're 2k in a fresh RMP with new friends, at least that's how I feel when playing RMP with pugs.
Melee cleaves are decent with a Priest, FMP isn't as strong as it was last season, might be better now with feral being rebuffed though. Boomkin/Monk or Rogue with a Priest is also not only good but extremely fun to play as Cippi has mentioned.