Because of the various flame wars and pirate raids from other boards, I took a break from praising HackMaster for a while. I think the game itself deserves support, though, so I'll make my comments and let it stand at that.
HackMaster is a game with a sense of humor, not a joke game. It's solid, and improves upon 1e and 2e in cool ways, too many to enumerate here. However, the individual DM needs to look carefully at the rules, and decide what he wants to use and what he wants to set aside - otherwise the game could collapse under the weight of its own rules.
The game has its own "feel" to it, sort of like 1e, but ramped up and turbocharged. PCs are supposedly gone through very quickly, but judging by the length of time it takes to make a PC, I doubt that really happens in most campaigns - otherwise a good, long session of PC generation would be pretty much all a HackMaster group would be doing each time they gathered to play.
HackMaster could be played seriously, quite easily. The humorous elements, though, are some of the best parts of it, so I'd say try it out the way it's meant to be played at first.
The GM's Guide is a great resource, even for other D&D games - even 3e. Sure, there are a lot of HM-specific items in it, but much of it is random tables (a d10,000 encounter chart, extremely detailed crit charts, the Smartass Smackdown Table, etc.) that can be easily ported.
The GM Shield is, in my opinion, the single finest example of a GM screen ever made.
They used their new Monster Matrices (like templates) to add variations to these monster as well ("Swack Iron Dragon: Hissing"). Later on, if you get into the game, pick up the 8 vols 1 or 2 at a time. Kenzerco's site usually puts a couple of them on special each month.
