The lead character always gets the limelight. In video games the star of the show will appear on the box art and in all the promotional material, while everyone else stands around in the background. Seeing as Mass Effect 2 hits stores this week, bringing with it a whole host of memorable characters who join you on your adventure, we've put together a list of our Top 10 Video Game Companions. These guys, girls, animals and inanimate objects all played their part, travelling with you, fighting alongside you or just offering advice.

10. Weighted Companion Cube - Portal


Valve must have been taken aback by the popularity of Portal's Weighted Companion Cube. Despite being just a waist-high grey crate with pink hearts on the side, the WCC instantly won a place in the hearts of gamers everywhere. Why? It's hard to say, but it certainly helps that the box is essentially the only "friend" you have in the cold and clinical trials of Aperture Science. As the psychotic computer AI GlaDOS bullies you from one task to the next, there's something quietly reassuring about the Cube's silent, enduring presence. Despite meeting a tragic in-game fate, the WCC lives on as an internet meme and - for the asking price of 30 dollars - as your very own plush toy, still available to buy from the Valve Store online. No, really.

9. Navi - The Legend of Zelda: Ocarina of Time


From the moment Navi woke Link from his nightmarish slumber at the beginning of masterpiece Ocarina of Time, we knew the chirpy little fairy guide wouldn't leave our side. Sure, she sometimes annoyed the hell out of us, with her incessant "hey", "watch out" and "listen", but her heart was in the right place. She was only trying to help, after all. Somehow, Navi - essentially little more than a bright white spark that followed Link around - managed to capture the hearts of the Nintendo fanboy horde. We loved Navi, and she loved us back. With her by our side, you never really feared anything.

8. Otacon - Metal Gear series


Hal "Otacon" Emmerich is a total geek. He works with computers, loves watching animes, and he pisses himself in terror when he's threatened by semi-invisible robot ninjas. In short, he's one of us, and his lovable nature makes him a geeky foil to Solid Snake's tough guy act throughout Metal Gears 1, 2 and 4. Whether he's helping you out directly through the use of a remote-controlled Metal Gear, blathering with you over the radio or mourning the death of a loved one (poor guy), Otacon is one of those gaming allies who permanently etches himself into your mind.

7. Urdnot Wrex - Mass Effect


Wrex liked killing people. Lucky for him, he was extremely adept at doing it. It wasn't just his huge frame, or his deep, booming voice, or his skill with a shotgun that made him tidy in a scrap. It was all of these qualities added together. Wrex followed Shepard just for the hell of it ("a storm's coming, and you and Saren are right in the middle of it"), and for that we loved him. But the Krogan Battlemaster's blood lust often made you laugh, too. He didn't speak often, but when he did, you'd listen, and you'd take him out on missions just to see if he had something particularly brutal to say about the carnage Shepard and co were causing. Our favourite Mass Effect character and a worthy companion on your quest to save the galaxy.

6. Agro the horse - Shadow of the Colossus


Shadow of the Colossus is a lonely experience, a bewildering game in which you're never completely sure of the morality of your actions. You quietly make your way across the game world, until you reach one of your giant opponents, battle them to the death, and then continue on your way. Throughout your quest, Agro the horse is your one and only friend - someone who is always there for you, who never questions your actions, regardless of how you may personally feel about them. You never exchange a word, obviously, but the bond that builds between you is an incredible thing, one of SOTC's many remarkable achievements. And of course, this companionship plays a vital role in the game's emotional conclusion.

5. SHODAN - System Shock 1 and 2


Okay, so we're being a bit liberal with the definition of "companion" here. SHODAN certainly isn't your friend, but she's an enduring presence who remains with you throughout your adventures in System Shock 1 and 2 - and indeed long after the game has finished, if you're susceptible to nightmares. Like the dual influence of Atlas and Andrew Ryan in BioShock, SHODAN is a character who is built almost entirely around her voice... and what a voice it is: SHODAN's icy mechanical tones, echoing through the shadowy corridors of the Von Braun spaceship, are enough to make your blood run cold - even on the rare occasions when she's working with you. She's the world's most advanced AI, she's utterly evil, and she could eat both Skynet AND Andrew Ryan for breakfast. Be afraid, be very afraid.

4. Tifa Lockhart - Final Fantasy VII


Tifa Lockhart, Tetsuya Nomura's confident, no nonsense Final Fantasy VII vixen, was a perfect foil for Cloud's emo musings. She wouldn't suffer his moping, and often chastised him for being such a grump. As adept with her fists as she was with her feet, Tifa proved immensely popular with series fans. Really, she's a pin-up girl for the gaming generation, and the role-playing genre's Lara Croft. If there is to be a Final Fantasy VII remake, or a new Final Fantasy game set in VII's mechanical world, Tifa's re-imagining would be of more interest than Cloud's or indeed Sephiroth's.

3. Dogmeat - Fallout Series


"You see one mean-looking dog" read the in-game description in the original Fallout. They weren't kidding, either: Dogmeat was so much more than just man's best friend - he was a furry little killing machine who would frequently save the player's life. In Fallout 1 you found him in Junktown, ferociously barking at strangers near the spot where his last master died. If you then put on a leather jacket or simply gave him some food, he'd be your buddy for life. Gamers went to great lengths to protect their little pooch, way beyond his intended lifespan, to the extent that there are still strategy guides online that explain how to keep him safe during Fallout's dangerous endgame. The mutt has since gone on to appear in Fallouts 2 and 3, but it's arguably his first appearance that remains his defining role. He's a dog who knocks bandits off their feet and then bites their crotch until they die. What's not to love?

2. HK-47 - Knights of the Old Republic


BioWare's Knights of the Old Republic did an amazing job at creating an olden-days slant on the Star Wars universe, but every once in a while it got a little bit too pious for its own good. If you opted to follow the light side of The Force you were pretty much forced to play as a simpering goodie two-shoes, so when you stumbled across HK-47 in a robot shop on Tattooine, he was a breath of fresh air. Oh he seems nice enough the first time you chat to him, but as soon as you've paid for him he reveals his true identity as an electronic equivalent to Patrick Bateman. HK-47 is a natural born killer (or at least, a factory-made one) and he certainly loves his work. Aside from being very handy in a fight, he has a barbed sense of a humour and a habit of referring to humans as "meatbags". Both of these qualities went some way towards diluting KOTOR's squeaky clean morality.

1. Alyx Vance - Half Life 2 and Episodes


Gordon Freeman somehow manages to be one of those characters who attains greatness without ever actually saying anything, but at least part of his triumph must be attributed to Alyx Vance. As one of the first video game characters to successfully convey human emotion, Alyx plays a huge role in the dramatic rollercoaster that is Valve's master work. There's a memorable scene early in Half Life 2 in which, you, Alyx and the huge robot Dog all play together using the gravity gun; it's a quiet moment, but it's things like this that pay a huge dividend later on, when the three of you are fighting for your lives. In short, Alyx is the emotional heart of the Half Life series, and a strong contender for the best companion in contemporary gaming.

Who do you think are the best companions in video games? Let us know in the comments section below.