Downloadable content is now an integral part of virtually every major release, but many gamers are still unfamiliar with the concept. Here's a handy guide to PC Advisor's favourite DLC.

8. Borderlands: The Zombie Island Of Dr. Ned

Borderlands Zombie Island Of Dr Ned

Gearbox Software’s sleeper hit Borderlands mixed compulsive, Diablo-inspired gameplay with anarchistic attitude, and was one of the first games to really deliver on the promise of downloadable content. All four of its updates were substantial and imaginative, but The Zombie Island Of Dr. Ned was the cherry on the cake: a loving, supremely challenging homage to kitsch horror movies that's more atmospheric than anything in the original game.

7. Mirror’s Edge: Time Trials Pack

Mirrors Edge Time Trials

In years to come game designers will look back on Mirror’s Edge as one of the most progressive commercial releases of its time, but as an overall experience it had one major flaw: guns. Fire-arms simply didn’t belong in DICE’s gleaming white obstacle course, disrupting movement and unbalancing the difficulty every time one appeared. The Time Trial Pack embraced this reality, trimming back the game’s many elaborations until it was left with nothing but an avatar, a timer, and geometric forms floating in space.

6. Enslaved: Pigsy’s Perfect 10

Enslaved Pigsy's Perfect 10

Judging from the sales figures, you probably haven’t played Enslaved: Odyssey To The West. Ninja Theory set new milestones in character animation and voice-acting but nobody turned up the show, and Pigsy’s Perfect 10 slipped by almost unnoticed. You switch roles from Monkey to Pigsy, whose guns, grenades and grappling hook completely alter the flow of the gameplay – Pigsy’s Perfect 10 is very much its own thing, but retains the standard of  writing and presentation that set Enslaved apart.

5. Red Dead Redemption: Undead Nightmare

Red Dead Redemption Undead Nightmare

Rockstar doesn’t deal in bad games. People tend to forget that. Red Dead Redemption should have proved once and for all that it was so much more than the house that Grand Theft Auto built, but at first Undead Nightmare inspired only apathy. Rockstar was accused of jumping on the zombie bandwagon, but that wasn’t quite accurate: Rockstar was actually making the only valid contribution to zombie videogames since the release of Left 4 Dead. Still, that L.A. Noire will probably be crap*.

*Trust me, it really won’t.