In the long line of tower defense games in which there are many variations, my favorite would have to be Vector TD by David Scott. I discovered this Flash game last year and instantly spent countless hours playing it and its two other sequals, Vector TDx and Vector TD 2. The game is similar to other tower defense games in which you must build fighters who will attack waves of the enemy as they wind their way through the paths to the goal. I’ve beaten nearly every level but the gameplay factor in tower defense games keeps me coming back as I try to find new ways of defending the castle.