The long-running giant mech series Armored Core is probably best known for its very deep customization schemes. Not only can you create the right mech for the right job, you can paint it any way your heart desires and add decals to give yourself a sense of personal branding. But most importantly, all this customization is very important for gameplay, giving you advantages in battle, and almost existing as sub game within the larger action. Tinkering with your mech will definitely take up a lot of your game time if you want it to.
For more information on what the customization entails, TeamXbox went straight to the source and got some inside information from Kenan Alpay, Associate Producer at Ubisoft.