Head over to EA's website to grab the "Mass Effect Bonus Content Download".

They contain concept art for Mass Effect 2 and 3, and though I've probably seen a lot of it before, I still get a kick out of seeing how character designs evolve through a game's development.

Mass Effect: Redemption issue 1 is set just after Shepard disappears at the start of Mass Effect 2, and explains what Liara was up to before Shep was found.

Mass Effect: Invasion issue 1 is all about Omega's Queen and CEO, Aria T'Loak, dealing with Cerberus trying to invade her space station.

The devs have also made a Mass Effect: Legendary Edition Custom Art Creator, which lets you build your own Mass Effect key art using all your fave characters.