Any game that IGN describes as ""Waterworld with mechs and no Kevin Costner"" definitely makes this list. The game revolves around you, the pilot of the world's only mech, and your part in a war for the remaining chunks of land in a flooded world.

The story wasn't the real reason Battle Engine Aquila was memorable, though, and rabid fans of the game will likely tell you first and foremost about how awesome the game's battlefields were. You may have been piloting the game's only mech, but each level dropped you into a virtual battlefield, where you could see enemies and allies battling it out. It gave the player a sense of scale that few other games on the PS2 offered, making the player feel like they were only a small part of a larger battle, rather than the end-all-be-all hero of the day.