Uff! It was a long time ago, but it was the Age of Empires demo. I had never played an RTS and I loved everything about it. Both my brother and I played it dozens of times before we got the full game.
Also the Civ V demo was so good that it sold me the game.
Please excuse my bad English.
Currently gaming on a PC with an i5-4670k@stock (for now), 16Gb RAM 1600 MHz and a GTX 1070
Steam / Live / NNID : jonxiquet Add me if you want, but I'm a single player gamer.