The Star Wars Prequel Triogy.
Edited by JeffJediWhich IP do you wish FFG had the license to?
Battlestar Galactica
This. Even a 1-wave spin off of the X-wing or Armada engines would be a blast.
X-Com
I would love to see a pair of linked Space Above and Beyond games, designed to be used in conjunction. Overall the game would resemble Imperial assault's psuedo GM approach, with one person controlling the chigs while the other players collaborate to control a persistant squadron, who gain abilities as the game progresses. A pilot/marine dies? Then you wait for a replacement and hope you don't get a rookie.
The space portion of the game would be much like XWing, and much of the time your goal is simply to get your troops to and from their missions as intact as possible. Whiel the land portion might resemble Imperial assault.
Or perhaps I just want an excuse to have a dropship and a couple of hammerheads on my shelves 
Hey ho! Let's go!
Star Trek. The Armada engine is literally crying out for Star Trek.
YUP! But it ain't gonna and I have the great ships already so it is way to late. It could of been glorious...
I'd love a dark souls game, maybe a card game somehow
Robin Graves, on 13 May 2016 - 01:58 AM, said:
Kamen Rider (let's see how many people here know this one...)
Always have been more of a Super Sentai man myself, but there would be serious IP issues there with the power rangers stuff and such so I'd settle for a Kamen Rider 
I'd love a dark souls game, maybe a card game somehow
How about a board game? not FFG but...
I'd like to see FFG take complete control of the Warhammer franchise. GW can keep making models, but FFG would control the rules. Then Warhammer games might actually not suck for awhile.
Which IP?
10.162.1.69
Crimson Skies would be epic!
Edited by ReaverRandallBabylon 5.
Even after all these years I would still be thrilled with a B5 space combat game.
Imperial Assault style Ghost in the Shell?
Overwatch...another candidate for the Descent/Imperial Assault style of game.
40k
I'd like to see a well done 'game of thrones' miniatures game. Maybe something like Imperial assault but set in castles, on ships, etc etc.
You could set it around the 'war of five kings' part of the story, each house has such distinctive armour, lots and lots of special characters etc etc
https://www.fantasyflightgames.com/en/products/battles-of-westeros/
I don't think it is quite active anymore, but it exists.
yeah i was thinking of something more like 'mordheim of thrones'
that looks a bit 'big units'/'risk' kind of abstraction. You know like 'this one horse represents an entire company of heavy horse.
Im not mad on abstracted games like that, i could be wrong though
edit: looks like i am wrong after a bit of googling, it slooks like a warhammer scale game with one figure being one figure.
It doesnt look terribly inspiring though 
Berserk miniture game. I NEED all the Berserk characters as 32mm minis to go with the upcoming Dark Souls board game.
Robert Jordan's Wheel of Time.
On a side. This could have been the next GoT if it wasn't tangled up in licencing.
The only problem with this is the HUGE world and how many storylines there are. Making this into a TV show or movie series would either mean you have to have 1 hour episodes every week for ever, or you would have to release 3 hour epic movies once a year. The biggest problem is how big the books are and they really don't take place over a long period of time, so without quick filming and releases, your actors would constantly be getting too old for the character. Harry Potter books at least were spread a year apart, so the actors aged with the series. Wheel of Time doesn't have that ability.
The books really aren't that big when you consider that the first THIRD of each one is just recounting what happened previously in the series. -sigh-
Back on topic, though, they've got Lord of the Rings, Star Wars, and Legend of the Five Rings, so what more could I possibly want?
(I guess I would be interested in seeing what they could do with Wheel of Time, though...)
Car Wars: Done up with a flightpath version of the rules called "Streetpath."
No backing up after an overlap 'cause you be crashing and smashing. Blocking takes on a whole different meaning.
Turrets would have a penalty of granting an extra avoidance die for targets out of arc. But missiles would be cheaper and using weapons lock tokens for reroll ability. Ablative Armour would replace shielding and you would have classes of vehicles such as motorcycles, sub compact, sedan, full size, truck, jeep, van, heavy vehicle, transport truck.
Actions would be:
Focus; like normal
Weapons Lock; like TL
Skid; Like BR but with an angular rotation
Hard Stop; reduce speed at the cost of stress
Ram; Reduce collision damage and increase output damage
Accelerate; like boost/slam but can be used to avoid a collision.
Spikes, oils, clouds and mines would still work as per normal rules
Guns, lasers, grenade launchers, flamethrowers as canon weapons.