I love Microsoft: The original Windows 3.x version of Tetris (the one made in 1990) runs just fine in Windows Vista :)  I've actually been carrying that version of Tetris -- all 76kB of it -- around with me since the mid 90s. Of course it requires quite a bit of window resizing to get it just right on a 22" wide screen!

Why do I and so many other people care so much about this game? The good folk at Graph Jam said it best:

Reasons to Play Tetris

A friend and I even organized regular Tetris tournaments at our undergraduate college during the late 90s which were hugely popular. Also, Tetris is the only game I've ever bought for my mobile phone. Yes, I am addicted.

Though, really, Tetris is less like a drug and more like a good cup of tea: it's perfect for any occasion. Whether you want to wake yourself up, relax before going to bed, keep your hands busy while talking on the phone or listening to a podcast, or do something when you have nothing else to do, Tetris is always the answer.

So thank you Microsoft and, more importantly, than you Alexey Pajitnov for creating such an awesome game.