If you could mix two games...

[Wonder Smash]

For games I would mix:

Mortal Kombat vs. Street Fighter
Tekken vs. Dead or Alive/Virtua Fighter
Soul Calibur x Final Fantasy

 

[LunarWingCloud]

Fire Emblem or Final Fantasy Tactics with Smash Bros. would be amazing.

 

[Dreamy Luigi]

Smash Bros. + Mario Kart= Smash Kart.
All Nintendo Characters are racing, instead of items you can do combat while you're in the kart (certain characters have projectiles that go far but don't do much damage, while close range combat does a lot of damage but not much range). It's a lot more technical than Mario Kart is atm.

 

[Nooph]

Pokemon and Elder Scrolls

"The Elder Scrolls V: Skyrim" + "Pokémon"

my mind is exploding just thinking about this.

 

[Heroine of Winds]

Kirby & The Legendary Starfy. People keep comparing the two when it comes to the cutesy themes. Gameplay-wise, they play completely different, but I think a game with these two franchises mixed together might create some interesting gameplay ideas.

 

[Matoi Knight]

Fire Emblem x Smash Bros.

I dunno, something seems cool about having the entire Smash Bros roster in a turn-based strategy RPG.

 

[OliverTwist]

Kingdom Hearts and smash! @_@ all the possible characters <3

 

[Deleted member]

Mega Man X with the gameplay of Mario 64 and have it actually be good.

 

[Spak]

Nintendo X Capcom, blending aspects and styles of both Capcom fighting games and Melee. It also might act as a bridge between the Melee and SF/MvC communities as they grow to respect the intricacies of each type of fighting game.

 

[YoPoYo9100]

Borderlands loot system mixed up with the gameplay and atmosphere of Dark Souls.

 

[Iceweasel]

I'd combine Xenoblade with either Pandora's Tower or one of the older Zeldas (LttP, LA, OoT, MM, or OoX). I'd have the dungeon design of Pandora's Tower/Zelda and the memorable characters, worldbuilding, epic moments, beautiful, massive overworld, and tons of sidequests from Xenoblade. It might be nice to throw a little Golden Sun into the mix too.

 

[CyberHyperPhoenix]

Project X Zone and the "VS Capcom" series. I'm sorry, but even with Capcom not having the Marvel license, a Capcom/Namco/Sega triple crossover Marvel style would be amazing and just seems like it would make so much sense.

Also, I'd kind of like to see some massive Mass Effect MMO thing. Like, have some giant war/conflict thing, and have everyone contributing to actual impacts on the outcome/conflict/story, etc. Though, I know some sort of massive scale super-multiplayer Mass Effect thing doesn't seem technologically feasible right now, it would be amazing.

Also SNK cuz Kyo :D

 

[VioletSmashfan]

Disney Infinity x Smash Bros (without the Marvel characters of course).

Then again Disney Infinity 2.0 has a mode that's just like Smash Bros, so there ya go.

 

[ProjectilePuff]

Metal Gear Rising and Fire Emblem Awakening.

I WANT TO PLAY AS A CYBORG NINJA DONNEL, DAMNIT!

 

[Dastardly Ridleylash]

Metroid x Fire Emblem, if only because it'd be pretty neat to have a Metroid tactical RPG.

 

[Omar_25]

Hotline miami + legend of zelda = amazing?
I've never played Hotline Miami, but I've seen it played.

 

[dezeray112]

Either Fire Emblem X Final Fantasy or Fire Emblem X Tales of series.

 

[Xavix]

Megaman X Metroid.
Two completely different franchises, centered around robot esque fighters upgrading their weapons to defeat a consistent enemy and to save the world. Honestly, this would be an amazing crossover, and I know Nintendo could potentially make this happen since they seem to give more love to the blue bomber than Capcom.
This is also the only smash couple that I ship

 

[Knight Dude]

Megaman X Metroid.
Two completely different franchises, centered around robot esque fighters upgrading their weapons to defeat a consistent enemy and to save the world. Honestly, this would be an amazing crossover, and I know Nintendo could potentially make this happen since they seem to give more love to the blue bomber than Capcom.
This is also the only smash couple that I ship

Not that bad of an idea. But I think the Mega Man X(and MMZero) series fits slightly better with Metroid thematically. The MMX series is a bit "grittier" which falls more in line with Metroid on the whole. It could still work with Classic Mega Man I suppose.

I think Mega Man and Kirby would also make for an interesting crossover idea. Those two take their weapons from enemies they've beaten too. Though the platforming is admittedly very different.

 

[ELITEWarri0r115]

Pokemon + Legend of Zelda or Kid Icarus

 

[Poppy JR.]

Jojo's Bizarre Adventure: The Platinum Games Character Action Game. Think Revengeance, but with stands and fabulous pompadours.

"What did you say about my hair?!" *Mash square to "Dorararara"*

 

[Cyn]

I'd want to see the term Metroidvania taken literally.