Reasons why Adoring Fan is the best Starfield companion:
Spoiler warning:

He doesn't care what you do.
If you shoot him either accidentally or on purpose he believes it was unintentional. He will complain about being hurt but it won't be directed at you.
If you are involved with criminals (eg Crimson Fleet etc) he doesn't believe it, so much so he talks about the lies people are spreading and how he defends your good name.
General banter is quite amusing, eg during combat he sometimes says things like "pew pew" and if he kills someone "that one isn't moving".
Gives you gifts all the time, like constantly.
When you take off from a planet he will sometimes say "weeeee" or "up, up and away".