Claremont's run (Where Wolverine, Colossus and Nightcrawler are introduced - from Uncanny X-Men #94 onwards) is pretty great. Its pretty much made X-Men what it is today and its arguably the best X-Men run there ever was and ever will be.
Honestly, if you don't want to go through 500+ issues of nonsense, you can always pick up from the 90s: There was a bit of a "reset", where they're split into two teams Blue and Gold. One's in Uncanny X-Men (from #281 onwards iirc) and the other in X-Men #1 onwards. It'll give you less to go through.
You can also go to "events" section of Marvel unlimited, just go through some of the X-Men related events.