Games
Games have always been a really important element in my life -- I love seeing interesting patterns develop during play.
Chess continues to interest me even though I stopped playing competitively since the 1980s. These days, I like playing through bite-sized tactical problems like the ones at ChessTempo during a break.
Gamut of games opened my eyes to the interesting world of games. I still recommend it as a great book.
Dungeons and Dragons remains my favorite game. I started playing in the early 1980s and have DMed a weekly game for Gita and our friends since 1987. It's great to see that D&D has become so popular in recent years.