All these games are easy to learn and are about 1- 1 1/4 hours max.
* Gulo Gulo and Chateau Roquefort - great kids games ages 4 and 6+ and only 15-30 mins.
* Guillotine is a wonderfull short card game.
* Say Anything and Wits and Wagers are brillant party / quiz games.
* Alhambra, Carcassonne, Settlers of Catan and Ticket to Ride are great games for families and adults alike.