1.Onslaught Tower Defence
Here it is the daddy of TD games, Onslaught. Rightly occupying our number one slot, Onslaught pretty much has it all. There’s a choice of maps, difficulty levels and even user-generated maps over on the Onslaught website along with a comprehensive guide to the game. But where Onslaught really shines is with the turret combo system. Not only can you get turrets that power-up nearby turrets, you can group turrets together in combinations that create devastating weapons… essential for later levels. Sadly there’s no end to the bad guys so you will ultimately lose but hey, there’s a mass of fun to be had in just mucking around with combos or chaining dozens of lasers together into one super-uber-mega beam of death.