Metroid and Halo: Metroid ranks as one of the longest-running, most beloved sci-fi gaming franchises of all time. However, it's impossible not to look at Samus Aran's space armor and think of Halo's Master Chief. Fans from the early 2000s couldn't help but compare the Metroid Prime franchise on the Nintendo Gamecube to Microsoft's Halo saga.

So why not blend the two together? While their styles are distinctly different -- Metroid being more an exploration game, with Halo being more action-oriented -- it isn't impossible to imagine a game that blends the two styles together.

Street Fighter and Darkstalkers: Street Fighter has previously crossed over with the Darkstalkers franchise in Marvel vs. Capcom, but these crossovers often take only a select few characters and mix them together. Street Fighter and Darkstalkers crossed over previously in the world of comics, but no attempt has been made to blend the games so thoroughly together.

It doesn't help that Darkstalkers hasn't had a game released in YEARS. While the voluptuous succubus Morrigan has made appearances in other games from time to time, that's...basically it. Any excuse to get more Darkstalkers content is welcomed.

Resident Evil and Silent Hill: Think of the survival horror genre. Two games come to mind: Resident Evil and Silent Hill. While Silent Hill has gone essentially on hiatus since Konami stopped putting the effort into good games, Resident Evil has undergone a revival, becoming a genuinely horrific horror franchise in its own right.

While zombies and parasites might not match up well with eldritch horrors and inner demons, it's impossible not to get a little excited imagining the Umbrella Corporation setting up shop next to Silent Hill.

Bayonetta and Devil May Cry -- Look, do we even need to justify this one? Both game franchises are the brainchild of mad game developer genius Hideki Kamiya. Both feature similar gameplay. Both are incredibly stylish and exciting games. Both have a die-hard fanbase that, to this day, wants more content.

So while waiting for Bayonetta 3 to finally come out, why not have this hair-centric witch get entangled with the Son of Sparda himself, Dante?

Onimusha and Sekiro: Onimusha is one of the forgotten gems of the PS2 era. However, between the 2004 and 2019 remaster of the original game, only two Onimusha titles have been released. The franchise needs a revival. One way to revive it? Cross Onimusha over with From Software's Sekiro: Shadows Die Twice.

Sekiro's style is certainly far darker than Onimusha's, but Sekiro essentially reinvented the samurai action game genre overnight. Onimusha could learn a thing or two from this iconic game if they ever crossed over.

Pokemon and Monster Hunter: Pokémon needs no introduction. Now celebrating its 25th Anniversary, the Pokémon franchise remains one of the top-selling game franchises of all time. You catch Pokémon, train Pokémon, but have you ever imagined a game where you hunt Pokémon and wear them as armor and weapons? If so, you might LOVE Monster Hunter, one of Capcom's most successful franchises.

But what if you were to combine the gameplay and action of Monster Hunter, but, instead of hunting a Ratholos, you hunted Rayquaza? It's impossible to argue that a Pokémon/Monster Hunter crossover wouldn't be one of the most exciting things to happen to both franchises.

Mortal Kombat and Tekken: Many people would love to see a crossover between Street Fighter and Mortal Kombat, but, presumably, these people have never played Tekken before. While Street Fighter and Mortal Kombat both focus primarily on 2-D fighting, the slower, more calculated style of fighting available in Tekken might be better suited for Mortal Kombat.

It also helps that Tekken remains one of the best fighting game franchises ever developed, despite being less popular than Mortal Kombat or Street Fighter. It would offer Tekken a chance to show it can compete with bigger franchises, especially following the lackluster Street Fighter x Tekken.

Mass Effect and Star Fox: While Mass Effect: Andromeda left a bad taste in everyone's mouth, there's no denying that the Mass Effect trilogy is a classic gaming franchise for a reason. While it limped across the finish line, it offered an immersive, fun experience for players everywhere. However, Andromeda was so bad that the only way to draw players back in is by offering something...completely insane.

So cross Mass Effect over with Star Fox, one of the original space adventure games. Sure, this crossover sounds ridiculous, but that's only because it is. It's so strange, in fact, that even if you thought it would be the dumbest thing in the world, you'd at least want to check it out, out of sheer morbid curiosity.

Uncharted and Tomb Raider: The Uncharted franchise feels in many ways like a spiritual successor to Tomb Raider. It only makes sense, therefore, to cross the two titles together in a combined adventure game.

This is far from the most inspired choice on this list. This is no doubt one of the first crossover titles you expected to be on a list of crossover games. That's only because, however, it's just such a natural choice for a crossover title.

Fire Emblem and Final Fantasy have crossed over thanks to Super Smash Bros, but that franchise is ultimately a fighting game for a group of friends. It isn't a hardcore RPG or complicated strategy. If the two were to cross over in a legitimate game that combined the best of both worlds, it needs to be a Final Fantasy Tactics-style strategy RPG.

While this might only appeal to a small niche of players, that doesn't make it any less of a great game idea.

Dark Souls and The Legend of Zelda: Dark Souls is one of the bleakest fantasy titles of all time. It's incredibly hard and unforgiving for new players. While crossing it over with one of the most mainstream fantasy adventure games of all time -- The Legend of Zelda -- might seem like an odd choice, it really isn't.

Zelda has over the last few years stylistically reinvented itself. Breath of the Wild and the Hyrule Warriors franchises are unlike anything else Zelda has ever offered. A crossover with Dark Souls might offer a Zelda adventure through From Software's distinct style.

Castlevania is one of the oldest gaming franchises of all time. However, again, thanks to Konami, new games have been slow to hit the market. Castlevania has essentially, alongside Metroid, birthed its own subgenre of games -- the Metroidvania games.

No, we're not saying cross Metroid over with Castlevania -- though that would be incredible. Rather, cross it over with a game franchise that drew HEAVY inspiration from Castlevania: Bloodstained. This independent gaming franchise has become an overnight hit with old-school Castlevania fans. Why not combine the lore of each together into one super Metroidvania game?

Ninja Gaiden and Ghouls'N'Goblins: Ninja Gaiden remains one of the hardest games of the NES era. Even during its revival on XBox, Ninja Gaiden has a reputation for being one of the hardest games of all time.

However, so does Ghouls'N'Goblins.

Yes. Ninja Gaiden. Cross it over with Ghouls'N'Goblins in a retro-NES style revamp of both franchises. It sounds absurd and crazy, but with both franchises going through a substantial lull in popularity and new games, it might be time to create arguably the hardest game ever conceived.

Call of Duty and Left 4 Dead: Many people just play Call of Duty for the Zombies mode. Yes, Call of Duty is one of the biggest gaming franchises of all time, but what do you really cross it over with? Would a Call of Duty and Battlefront game really be different stylistically? Rather, wouldn't it be more interesting to double-down on the Zombie material, and just combine two of the best team-based zombie games around?

Call of Duty Zombies? Cross it over with Left 4 Dead. Combine the unique zombie types from Left 4 Dead, as well as level design and team-oriented gameplay, while combining it with Call of Duty's intuitive FPS gameplay. It might be a mess of different zombie styles, but it would undeniably be a fun game.

Senran Kagura and Dead or Alive: Senran Kagura has a well-earned reputation for being a perverse ninja game where girls run around with far less clothing, fighting until their clothing falls off. It might not make logical sense for it to rank anywhere on this list, but there is another equally pervy gaming franchise that revels in showcasing its sexy cast: Dead or Alive.

Crossing over Senran Kagura and the Dead or Alive franchise might not seem logical, but given the previous entries in both franchises, it's hard to come up with an argument why fans of both franchises wouldn't benefit from a crossover.