The League of Gentlemen (or constituent parts) did great commentaries for Theater of Blood and Blood on Satan's Claw, both of which are worth owning on DVD or Blu and laughaloud funny.
Roger Moore on his Bond films (especially Man with the Golden Gun).
Darkplace (in character, but excellent).
I'm Alan Partridge (series 1 in character, and all the rest just with writers etc)
Any one with both Simon Pegg and Nick Frost is very good. Simon and Edgar can be a little more luvvy, bit Simon and Nick are a great combo.
Del Toro pissing himself laughing at Damascinos' wig on the Blade 2 deleted scenes commentaries (which is a very deep dive) has stuck with me forever.
All Carpenter commentaries are good and the Russell ones mentioned above are indeed the highlight, but the Roddy Piper one for They Live is very funny.
I've always wished for a decent sharing community for these sorts of things. I know the Criterion Tap commentary (the non-character one) is clamored-after as it never hit the UK releases.
Also, the Simpsons and Futurama commentaries were always excellent, and the one that really sticks out is for the otherwise awful Bender's Game. Check that out, the commentary is hilarious.