I just finished running my PCs through the TSR-era Advanced Dungeons and Dragons module N1 Against the Cult of the Reptile God. It’s oft-cited as a favorite classic module and as a good 1st level/beginner module. Unfortunately, it’s highly overrated.

System: The Green Hack (my variation of The Black Hack designed to improve compatibility with TSR-era modules). Number of sessions: 4

The Good

• The village portion of the adventure was more fun than I thought it would be. The players seemed to enjoy fleeing the Golden Grain Inn, where the bartender tried to poison them, exploring the ruins of the Foaming Mug Inn, and questioning various people around town. It was a nice way to tee-up an adventure — more interesting than merely being pointed at a dungeon by a quest-giver.

The Bad

• The most common criticism of the adventure (apart from the fact that the labyrinth under the Merikka temple is impassible) is that the PCs pretty much have to recruit an NPC named Ramne to accompany them on their dungeon delve if they want to have any chance of surviving. As many have pointed out, this ends up making the first-level PCs feel a bit second-fiddle to a high-level GMPC. This is indeed a problem and, short of nerfing the naga and some of the other creatures in the dungeon, it’s not an easy problem to solve.
• The bigger issue with the module, however, is that the dungeon was stocked primarily with hostile creatures, leading to combat after combat, with few non-combat problems to solve or things to interact with. The dungeon really needs some factions, some rooms that have something in it besides traps or monsters that attack on sight. One of the better encounters is an underground lake full of crocodiles that the PCs had to find a way to cross. It could have used more problems like that.
• Although the village investigation was fun, it also felt a little pointless. There wasn’t much, if anything, the PCs discovered on their own that Ramne didn’t already know. It was another way that he ended up overshadowing the party. If you wanted to skip the village investigation altogether, you could just have Ramne hire the PCs to accompany him on an excursion to the dungeon.
• As mentioned above, there’s an error in the book: there’s no way through the labyrinth under the temple. I just took the whole cellar out, since the troglodyte tunnel encounter after the labyrinth wasn’t very interesting anyway (there are plenty of troglodytes and tunnels in the dungeon proper).

The bad definitely outweighs the good for this module. A skilled GM could probably probably fix it up by either nerfing Ramne or nerfing some of the dungeon encounters and adding some variety to dungeon. But there are plenty of ready-to-go modules out there already. The Village of Homlet can also feel like a bit of a monster bash, but it at least has a few more opportunities for PCs to experiment or turn factions against each other. I haven’t played any of them, but there are now a few interesting looking newer (than TSR-era) level 1 adventures, including the free, beginner-oriented Tomb of the Serpent King.