I've very recently been getting back into chess, what is considered the main rating on chess.com? Is it Blitz, Rapid? I've noticed rapid scores are noticeably higher than say blitz mode.
Blitz or Rapid are the most reliable ratings in my opinion.
Bullet has a lot to do with having good reactions, and Daily with how much time you are willing to invest.
Blitz players will tell you: "Blitz".
Rapid players will tell you: "Rapid"
Since I'm a Daily player, I'll tell you the truth: "Daily".
bullet is the main one because it is the only one I am above 2k in. That is the truth.