Call in sick for work and lock your doors....
Even today, over two decades after it was released, Starcraft still stands proud as a highly addictive poster child for its genre.
Simple in concept, with an excellent story-based campaign, and beautifully executed, Starcraft has all the replayability and enjoyment you ever wanted from a video game.
The only criticism i could possibly think to make is that Starcraft is too easy, but you won't care once you fall in love with all the good things it has to offer - and the expansion, 'Brood War', adds enough variables to dispel that criticism.
If you've been living in a cave during your distinguished video game career, or if you just never picked up this little gem, i couldn't recommend buying the starcraft battlechest (game plus expansion) more.