I never experimented with it that much. My only test was asking people to like and subscribe versus not. My intuition would be that you should use the phrasin

I never experimented with it that much. My only test was asking people to like and subscribe versus not. My intuition would be that you should use the phrasing that is authentic to your channel and voice. Most of my content was reading quotes from government reports, academic research, and news reports and then explaining what I thought about it in a calm monotone. (My vocal inspiration was Sam Harris). At the end of my videos I said "If you enjoyed this video please let me know by clicking the 'Like' button. If you'd like to see more content in a similar style, please subscribe." Which I felt represented the tone and pace of my videos. On the other hand, if your channel is faster paced, more energetic, focused on being funny etc, then you probably should come up with a wacky or creative way to say "like and subscribe." I don't think anyone is going to subscribe just for how clever your saying is, but it will be more consistent with the tone of the channel. I think the main benefit of saying "Like and subscribe" is just to remind people to do that. Some people will be watching your video and enjoying it but just need an extra push to think "Oh yeah, I should subscribe, I do like these videos."