If you haven't heard yet, Goodman Games has a beta of their Dungeon Crawler Classic rules, get it right here.
I have looked over the beta a few times and I like most of what they have. This is not the heroic AD&D, this is gritty and harsh. I fucking love it! I plan on trying to get some guys together for a short game or two. But, it has already burrowed its way into my head.
Luck is involved in this game. Thieves need it for a boost to skills. Fighters get it for extra boost to a weapon. Wizard and Clerics get it for helping get through spell checks. This is an amazing little rule that I have added it to the 1st edition AD&D game I am working on. I need to change a few things, but hey, it happens.
Also, another thing I am adding is the way magic works in DCC. Two things happen in DCC. One is whenever a magic user learns a spell, something weird and/or bizarre can happen. Wind could shoot out from the wizard, tiny demons could spill out and surround the caster for a few rounds or it could be harder for him to cast the spell. Also, there is a mechanic called corruption. Arcane magic is dangerous again. This is something I have been looking for, to make magic strange again. Clerics have their own deal as well. I highly recommend this game after just skimming it.
However, a warning, this is not a complete set of rules. This is just a beta. You take characters from 0-3, (YES, you have to start at lvl. 0), in a short campaign. The rules come out in November--I already have my copy pre-ordered. I am looking forward to it.