Yahoo! Towers
When I was back in high school, there was no access to video games everywhere I went. Peers with laptops wouldn't show up until college cell phones came in the flip variety. It was pretty exciting when I realized I could head to the computer lab at lunch and load up a non-newgrounds SFW flash browser game (a rarity at the time). Enter Yahoo! Towers.
There was nothing special about this game, a simple match puzzle game, but I played this game a lot. Keep in mind, I only played Yahoo! Towers for about 2-3 months, but the obsession came fast and hot. In those last few months of school before summer I'd play it every lunch hour, then much more when I got home. A relatively unknown game, Yahoo! Towers holds the title as the only puzzle game I've ever actually dreamed about. No, literally. I still to this day find it odd that I had an entire dream that consisted of nothing but a flash game interface and falling bricks. I went back and Yahoo! Towers is gone. It was replaced by hundreds of far superior games ranging from mmorpgs, puzzles, action, card, and other games. Kids today get everything.