Steve Jackson Games, 1982, 2-6 players, ages 12 and up. In Illuminati, each player plays one of the mysterious dark powers that secretly control our world ("The Network", "The UFOs", "The Bavarian Illuminati", "The Gnomes of Zurich", et al). Using their base group, they attempt to take control of various other political, economic, and societal groups that make up this paranoid vision of the world (Fast Food Stores, The Mafia, Cattle Mutilators, The Democrats, The Republicans, The Clone Arrangers, and on and on) in an attempt to build the most powerful secret organization and win the game.
Turns consist of drawing income for each of your groups that can earn money and then drawing cards. Cards are either new groups (added to the "uncontrolled" stack) or specials (cards to be saved and used in special situations). After drawing cards you attempt to control, neutralize or destroy groups (either uncontrolled groups or groups that are under the control of other players). Success is determined by the power and alignments of the groups you use in the attack vs the resistance and alignments of the group you want to control - with money thrown in to sway the balance one way or the other. Once taken, a new group is added to your power structure. The game is won when a player gains control of a specified number of groups or they meet their special victory condition (different for each major power).
This is a classic game that we have been playing for years and years. Half the fun is reading all of the insane group names they come up with, which generate some really strange bedfellows ("The Bavarian Illuminati, aided by the Democrats and the Door-to-Door Salesmen, attempt to take control of The Soccer Moms"). Game pieces consist of cards and money and that's about it. The rules are well-written and easy to follow. The original game was woefully cheap with tiny black-and-white cards and microscopic money chits just begging for somebody to sneeze and wipe out the game. There were also a number of early expansions that added new rules, abilities, powers and groups. Since then, SJG has cobbled it all together into a "Deluxe" set that contains the original game and all of the expansions with nicer cards and money chits. There was also some attempt to turn this into a CCG which involved the release of expansion packs of cards and deck-building rules and whatnot, but we never took the bait so I don't know how that all worked out. This basic system of building a network of cards was also used by SJG in their Hacker game.