Here is a really nifty adventure scenario that turns on the PCs traveling to the Nine Hells with a literal boatload of demons. The module is written for 15+ level PCs which perhaps makes it overpowered for most campaigns, but the writing and plotting (no pun intended) is quite good and realistically deserves 4 1/2 stars.
TSR/WoTC has thrown off the self-imposed "PG-13" standards of the bad old careful days and embraced the NC-17 world with this product. There is nary a tanaari or moronic Blood War to be found here, this module is rife with devils and demons that want nothing more than to kill you, devour your soul and use your blood to create pentagrams. Seriously, this product is not for children, the weak of stomach or anyone whose religious sensibilites are easily offended.
And, really, that is how it should be. Too often, AD&D devils and demons are presented simply as another monster with a set of stats instead of the living embodiments of pure evil that they are and A Paladin in Hell goes to great lengths to demonstrate just how vile the legions of the Nine Hells can really be; this product has the chance to do for devils and demons what Ravenloft did for the vampire. While the violence and evil deeds written into the scenario are not gratuitous, a slice of Hell is really served up in a realistic and shocking manner.
The product is not only subjectively nasty, it appears extraordinarily difficult even for PCs of the recommended power. The early sections of the scenario did not appear overly dangerous, but the final chapter is likely to lay some serious hurt on even very high level PC parties so players beware.
Not that Paladin in Hell is simply a brutal hack and slash adventure, in fact, for the PCs to succeed, they must do far more than just kill off every hellspawn they can find (and there are plenty to be had in the Nine Hells). There are ample opportunites for role-playing as the PCs seek to solve the mysterious disappearance of a lawful good temple.
While the product was written with some loose Greyhawk tie-ins (Emirikol the Chaotic makes a cameo appearance), the product can be run in any campaign with minimal adjustments. The only real drawback that the product has is the need for ultra-powerful PCs; few home campaigns routinely have 20th level PCs. Paladin in Hell might be best run as a one-shot adventure (though it will still likely require several play sessions to complete), but the product is also quite useful in that it provides complete information on spell, magic item and class ability alterations incurred whenever your PCs travel to the Nine Hells or the Abyss and that alone makes Paladin in Hell a good buy for any DM that employs extraplanar travel and creatures on a regular basis.