I like rapid, but bullet can help you think more faster and there is pattern recongition
Blitz, Bullet or Rapid: which format helps you improve more?
I prefer rapid as well because sometimes people think they can make me quit by just wasting their entire timer.
And Bullet improves you at chess to play faster like you have 10 seconds in a game you would know how to react!
I think in order to learn the game, the slower the match the better. Also, if you play a friend who is much better than you are and they are cool with it, have them explain why they are making the moves they are as you play. They will still likely win against you, but you will get to see in real time how and why they are doing so.
I prefer rapid. I need a bit more time to think things through. But I can think really fast when I'm playing variants like bughouse.