How old are these books you're talking about? If it's 3.X, I suggest Epic 6 [http://www.myth-weavers.com/wiki/index.php/Epic_6] because I love it. And you must try to please me. Also, it's awesome if you want a more balanced and interesting system.
Other than that, for a while now I've been thinking of running a campaign with the typical dungeon trekking but have an NPC accompany the players (might not even fight - could be rescued from there or they hired the PCs as escort). The said NPC would constantly blabber about the "cursed" dungeon and how strange things happen there. But would secretly be a rogue that filches their money and makes up the magic as an excuse. If the group manage to sniff out the rat, more power to them. Otherwise the rogue might turn into a recurring character who tries to subtly double-cross the group all the time. It would be amusing to see how far it can go. (By the way, it would be totally in character for that rogue to hire the players to assassinate the ruler)
Or, if you think you can pull it off, use the Head of Vecna in your campaign.