My Intellivision still works (it's flaky though - hit it gently and it resets) but I love the original controllers. Nothing was better than playing another seasoned player in Baseball, where each fielder was a keypad button 1-9 you had to activate immediately when the ball was hit. The Intellivision 2 (white controllers) were REALLY bad, and trying to push in those side buttons was really hard on the thumbs. The only good thing about them is they plugged in and out, unlike the original controllers that were hardwired to the main unit.
The Intellivision disc had 16 directions, not 8, which was great for sports games, Tron Deadly Discs, Armor Battle, and many others where top down movement and firing were the crux of the gameplay.
Sea Battle, Utopia, B-17 Bomber, and AD&D Treasure of Tarmin were and still are my favorites.