was the original highlander that big of a hit that it needed a reboot? i remember it being a small movie and it gained popularity on cable, then they made a couple of terrible sequels that nobody watched either.
i know they made a TV show for it, i couldnt bring myself to watch. christopher lambert is the only connor macleod. and he had an arc in the first one that finished by the end of the film.
The first movie really is a self-contained arc. All of the sequels had to come up with weird stories to get around the fact that the first movie ends in such a concrete way. Connor becomes the final immortal at the end of the movie, story over. In a way it's unfortunate that the first movie had such a concrete ending to it because it walled them off from making any sequels (or, really, made it super-awkward and clumsy to do sequels).
2nd movie: More immortals arrive from another planet, their arrival "un-does" Connor being the last immortal so he can defeat them and become the last immortal again. Also the movie is horrendous, only slightly saved by Lambert and Connery being fun to watch as a pair in the present day.
3rd movie: Some immortals trapped underground for thousands of years are freed, for some reason the Gathering went on without them, this "un-does" Connor being the last immortal so he can defeat them and become the last immortal again. At least this movie is actually kind of good, unlike 2. It has a tremendous montage midway through when Connor has to re-forge his sword, and in general it's just a fun movie. Doesn't accomplish much, though, because it's basically just a retread of the original movie without being quite as good.
The series is its own huge beast. IMO it's a great TV show, and worth seeing. The only issues with it: A) The series can get very redundant as each episode has Duncan Macleod battling a new "foe of the week". Sometimes these stories are great, sometimes they're not. B) It conflicts with the original movie, like everything else does, by having all of these other immortals running around after the movie said there were none left. However, to their credit, they spend the first episode retconning the movie by having Connor Macleod show up and pass the torch to Duncan (Connor can't quite defeat the bad guy, then Duncan fights the bad guy and wins) while explaining that Connor's fight with Kurgan was just one particularly huge fight between two of the top immortals, but it wasn't the Final Two. So the series actually recognizes the canon of the first movie, only without that one "final immortal" detail.
The show gets better and better as it goes on. Seasons 3, 4, and 5 are some of the best TV I've ever watched. 4 and 5 in particular get really creative with stuff like the main character temporarily turning heel and the Four Horsemen of the apocalypse showing up (turns out they were a faction of immortals). It's a pretty slow start with seasons 1 and 2 and combined with the redundancy of the series in general, I think this slow start keeps a lot of people from getting to the really good stuff. Though S1 and S2 each have a couple of standout episodes that are must-see, so they aren't exactly skippable either. Season 6 is super weak because the show should have ended with S5 and they dragged it out a bit longer, but at least it's short.
The 4th movie (Endgame) actually serves a purpose because it functions as the final episode of the TV show. It isn't bad at all as a movie, though it violates a bunch of series rules and tries a little too hard to be "badass and cool" at the cost of characters not acting like themselves. A lot of movies that follow up on a series do these things: Star Trek Nemesis, Serenity, etc. I'm glad Endgame exists because the show needed one final Big Bad type enemy to close it out IMO. Plus we finally got to see Connor and Duncan battle it out here.
The Source (5th and final movie) is complete and utter dogshit that is supposed to be a follow-up to the series as well, but doesn't follow series canon or have anything to do with the series. Characters act completely out-of-character, it kills everyone off, and the plot makes zero sense. Everything remotely Highlander about it goes away after the first 15 minutes or so. For example, Duncan's iconic sword gets broken and he uses knives after that, the immortals all turn mortal for some reason, etc. I'm about 90% sure the script of this movie was written for a completely different movie and they decided to use the Highlander name to give it a boost. When it became too hard to write like that, they just turned everyone into normal humans and did the rest of the movie that way. We don't even speak of this movie at the dinner table.
While I'm at it, here are all the timelines you could follow in this series that are their own canons:
Highlander (self contained)
Highlander -> Highlander: The Series -> Highlander: Endgame (the series' official canon)
Highlander -> Highlander 2
Highlander -> Highlander 3
The Source is dogshit and doesn't count anywhere or fit into any canon that I know of
Not looking forward to seeing the reboot if it ever happens, though Cavill turned out to be pretty good in Witcher. It will be interesting to see if they do what the original did and have the movie be a closed arc, or if they have it the way the show retconned it to leave open the possibility of doing more with the character/universe.