CM1-The Known World?
I never played any of the CM series. Once I realized that basic D&D was slanted against evil to the point where they eliminated the alignment from the game, I was out. Plus AD&D had lots more arcane rules and confusing graphs. That said, one of the reasons I am plowing through all the modules that I can easily download or pirate is to see what I may have missed. One module in I can say: not much.
To be fair, CM1 is not designed to be a traditional module; it is more of a campaign setting with a couple of set pieces in it. The dungeon of Kwyll has a bit of a Vale of the Basilisk feel to it: the party gets to fight a red dragon named Smokynose, a handful of trolls, and a beholder. Any and all of these offer good, clean, hack and slash fun. The encounter with the Greek-legend/Krull inspired three sisters is another good battle, although I am not sure what is gained with the big Atlantis reveal.
But mostly this campaign is what I already don’t like about the basic rules: PCs are supposed to be good. Look at the list of pre-rolled characters: Fergus the Justifier [Lawful], Quillian Elm-Grower [Lawful], there is even a Lawful thief, which is all kinds of confusing. PCs also don’t get much volition in which side they should be supporting: maybe I hate Atlantis or really like partying with frost giants. In either case, the campaign’s narrative does not provide the DM with any guidance on what to do if this happens; the assumption is that characters will immediately come to the aid of who they are “supposed to,” instead of who they want to.
But never yuck on someone else’s yum is a rule I live by, and if someone wants to play a lawful fighter carving out a small kingdom in newly discovered country, go for it.
Also, there is barbarian wrestling.