Nethack : old school roguelike

Tale of Maj Eyal : removing of tediousness in old school roguelike

Baldur Gate 2 : D&D implementation

Civilization 2 : just one more turn

Fallout 2 : narrative based on character build

XCom : tactical combat with base building

Jagged alliance: tactical combat with squad building

Knight of Legend : best original turnbased combat system never done again

Slay the Spire: For deck building

Quake: playing with friend