Let's just put a little twist on it. Instead of sequals, what games do you want a prequal to?

I want my .Hack//FRAGMENT... sure, the MMO was canceled, but I still want the story of the original version of The World.

I want a decent FF VII prequal also a Kingdom Hearts 2 prequal would be nice.
Yes I am well aware they both exist however only on shitty ass clown portables in a stupid attempt at squeezing a little more $$ out of us.

a prequel to half life 2-play as a soldier in the 7 hour war
GTAIV-play as niko back in europe
every WWII game ever-WWI (just to be different)

I wouldn't mind a prequal to Halo. You could play as one of the other spartans, should be fun. Or maybe a game based purely around the Covernant, hmmm...

Here come the insults.

Gears of War. i wanna know what happened at Aspho Fields.

I'd say Freelancer but it exists, its called Starlancer... But something Post-landing pre-expansion would be nice.

Prequel to Portal would be top of the list. Something based in around the time Apeture Science when Boingo Boingo Whoopsi Knickers.

Another nice possibility, a prequel to Battlefield 1942... IE, world war 1.

StarFox. I recall the N64 game's manual hinting that intergalactic pirates used to be a much bigger problem before the Cornerian Military wiped them out in Sector Z. Most known continuities also agree that Andross was exiled due to one of his experimental bio-weapons going haywire and killing everything around it (possibly including Fox's mother). Throw in the seeds of Fox and Wolf's mutual enmity starting at... whatever academy you go to on Corneria to learn to pilot starfighters... Cripes, this sounds like a CGI movie, not a game.

A prequel to Mass Effect would be pretty sweet - something about the different "backgrounds" you can choose for Shepherd, due to length, would probably only be suitable for dlc, but a whole new game about the First Contact War would be cool.

zma924:
Gears of War. i wanna know what happened at Aspho Fields.

A hundred times yes.

How about a prequel to BioShock? As Rapture is becoming the city we see in the game.

Altered Beast.
Who WAS the humble dude in underwear? HOW did he die? WHY did Zeus choose to resurrect him instead of anyone else?

A prequel to Halo would be great, fanboyism aside. There's a lot about the leadup to the war with the Convenant that would make for interesting sorytelling (were we friends with them when we first made contact? et cetera). And I love idea of playing one of the first Spartans to be sent into battle, armor malfunctioning, buggy AI, crap weapons. It would take some of the "Master Chief is an invincible metal God warrior" aspect out of the games that so many people dislike about the series.

MichaelH:
A prequel to Halo would be great, fanboyism aside. There's a lot about the leadup to the war with the Convenant that would make for interesting sorytelling (were we friends with them when we first made contact? et cetera). And I love idea of playing one of the first Spartans to be sent into battle, armor malfunctioning, buggy AI, crap weapons. It would take some of the "Master Chief is an invincible metal God warrior" aspect out of the games that so many people dislike about the series.

If you want to know the story before and after contact was made with the Covenant, I'd suggest reading the Halo book trilogy.

I also believe that Halo Wars will be set in the pre-Halo universe, when there were still dozens of Spartans and the humans weren't quite as near to their own extinction.

Fire Daemon:
I wouldn't mind a prequal to Halo. You could play as one of the other spartans, should be fun. Or maybe a game based purely around the Covernant, hmmm...

Here come the insults.

Now I never have cared about halos story. But if the spartans is the other super soldiers that Master Chief is the only survivor, I would like to see a prequel to halo.
And let see a prequel to FF7 and not like crisis core but before that, like who Jenova was and you'll play on her homeworld to find out the reason she traveled across the space

A mass effect or halo prequal would be quite nice for both an introduction to "human meeting alien" thing would be interesting

especially for halo

A prequel to Pitfall - I'd love to see how all that treasure got scattered throughout the jungle.

Also, pretty much any game with a multi-level dungeon in it. I'd really like to know the justification behind building such a structure and how it was populated with both monsters and treasure. Also how it was engineered to ensure the different populations of monsters coexist without slaughtering each other and supply all the resources needed to keep them alive and allow them to go about their daily activities. Must have been a monumental undertaking, and an interesting tale in pulling it all off.

Frosk:

zma924:
Gears of War. i wanna know what happened at Aspho Fields.

A hundred times yes.

How about a prequel to BioShock? As Rapture is becoming the city we see in the game.

They are making one. it's set for 2009

I'd really like to see a prequel to Halo, but the problem about prequels to games that feature mankind on the brink of destruction, is that you actually have to lose the game for it to fit the story in the original. I especially remember this problem from a N64 starwars game in which you had to play the battle of Hoth. To beat the level you had to defeat a certain amount of AT-AT's and AT-ST's the game threw at you. If you didn't destroy them within a timer or something you would fail the level. But when you had destroyed them all, the empire won anyway. This felt very odd since you had just cleared out all the invading forces.

How can you make a game, where the player has to push forward in a level, but still resulting in defeat?