Introducing the Terran Goliath from Starcraft II. Enjoy!
About this creation
Here are some poses, to show how stable it can stand. Granted, it's not exactly perfect, but it was designed to pose as a model, not necessarily to be played with.
The legs can bend. If you watch closely at the game's animation. The legs bend each time it fires at an air unit.
As for the cockpit. I couldn't find any references as to how a pilot got inside. I assumed he can either go through the top hatch (if that's a top hatch) or through the back (if it even opens) or through the canopy, all of which I have no idea, but luckily through the design process. The whole main body can be lifted open and it actually looks pretty cool.
You can find the instructions and parts list at my web site at http://www.brickformula.com if you would like to build your own. To change colors, just substitute all the red bricks for whichever team color of your choice.