I love all the Back to future movies, it one of my favorite movie trilogies ever to be convinced. I hold it above the original Star wars trilogy and I fucking love Star wars.
But there is one big problem with one of the movies, and that's the first part in Back to future 2, you know where they forward in time to save Marty's son to not fuck up his family rep in the future. But this whole part of the movie is stupid and pointless, and I will explain why I think so. Also I suspect this will not very coherent.
I have no problems with them going to the future, I think that is cool and it further adds to time traveling aspect of the trilogy. So it more the reason why they do it that makes it all stupid and pointless.
So even though Doc Brown is concerned about disturbing continuity he risks it by taking 1985 Marty into the future to save his son which happens to an exact replica of him. I get that go and ask Marty for help to solve this problem that will happen in the future, since Marty is the only person but Doc himself that is aware that time travel is possible. But why did he have to go to 1985 Marty for help? Couldn't he just ask the 2015 Marty to like ground his son that night he was supposed to be framed for a crime, (which slip my mind right now what it actually was) or better yet just tell Marty in 1985 to not raise his child to be a pussy and stand up for himself and fight his only battles, instead of having his father from 1985 do it for him.
So there really isn't any need Marty to come the future, since that led only to him fucking up the timeline worse than Doc could imagine by unintentional let Biff go back in time and give his 1955 counterpart that calender which lets him become a gazillionaire that owns the world.
But then again I know Doc only did this because he cares about Marty and his family well being, and tries to help as much he without fucking the timline to such a degree that the fabric of time and space will unravel. Oh wait, Marty's life sucks in the future because of that accident he had in 1985, which injured him in such a way that he could no longer play the guitar and become the rock star he always wanted, leading to him becoming a bitter old man with wallowing in regret and sorrow and also getting fired because he let his temper get the better of him. So yeah, one family crisis averted a bigger just over the horizon.
So what Doc just should have done was that he go back and tell Marty and to race Biff's son (name slip) and that he should not let himself be so easily manipulated by trolls.
So if Doc had just done that all would just fine for Marty and his family, hell he probably would become a rockstar even if doc just gave him little hints on what to do and not do instead of dragging his ass to the future to avert a minor crisis which led to an even bigger crisis when he could just have warned him in 1985 wiithout disturbing the continuity of time and space.
But that aside, Back to the future 2 is still a fucking awesome movie, and the second is probably the best in all of the trilogy since they really play around with the time traveling concept.