I've been thinking about this a bit. Series that could benefit from the Dynasty Warriors treatment. There are many possibilities here.
First a few rules and clarifications. This extends to you too, readers.

1. No exceedingly famous series, like Marvel or DC series. They already have too much love and have many games. (Regrettably, i'm going to have to add Pokemon here too, as there have been WAY too many versions of that to warrant another.) And unfortunately i'll have to lump MLP itself in here as well, though it would make an AWESOME DW crossover.

2. Precedents apply, which means i can also mention Anime, since Gundam and One Piece have been given this treatment already.

3. It has to fit the style of the series, so as much as I hate to do this, i can't put Deagon Ball Z on here, since it mostly focuses on 1v1 battles, so this is another reason Pokemon can't go down here.

Oh, and just in case

1.
Think about it. There are tons of likeable characters with lots of personality, clearly defined and widely varied movesets, an interesting backdrop and several scenes where they have to fight more than one opponent, though there are admittedly a lot of 1v1 fights, which is whiy it isn't higher.

2.
WAIT!
Before you X this window, let me explain.

God Eater may already have a couple of games, sure.

But i think that the Monster Hunter style doesn't do it justice. It doesn't give you the feeling of powerful vulnerability that you feel in the anime series.
They know that they can die at any time and that they're the only ones who can take down the Aragami. There are hordes of them in an impressive variety, increasing every day and the stronger a fighter gets the shorter his/her actual lifespan is expected to be. But at the same time, most of the enemies can be taken down in one shot, if you're fairly accurate! Even in the current games, most monsters (on the first ranks, at least) can be taken down with a few shots.

This is why i think that giving it the DW treatment would work better. Imagine, being able to roam around a field, slaying scores of weaker monsters, while larger ones might be... somewhat harder to deal with. Weapon customization could be a thing, as it is in the current games. There are lots of characters you could play around with, even create your own! Making it a medium-hard DW style game would be perfect!

3.
This may seem a bit of a stretch, but hear me out.
Anyone remember this game? (joking) I see.... three, four of you raising your hands?
Yeah, this game series is in need of more attention. Anyway, if you've ever played it, you'll know that it has an expansive world based on Norse mythology, many characters that you unlock as you go along, a decent rogue's gallery of demons, monsters and the undead. There are clearly defined lines between the three.
Each character is different, there are lots of things to do and places to go and has a lot of replayability.

This might make a good DW game. For all the previously listed reasons, Valkyrie Profile would fit in excellently!

4.

This is the last one i'm going o talk about this time,

I've been getting into this series recently. It's the Devil May Cry to Soul Eater's Bayonetta. or those of you who watch Josh Scorcher's videos, you'll kno what that means. For those who DON'T....

Devil May Cry features a not-so-serious character in a serious world. Bayonetta features a slightly more serious character in a MUCH less serious world!

Likewise, Fairy Tail has characters that try to be serious -and fail hilariously- in a world that doesn't screw around nearly as much, like in Dynasty Warriors. The characters are (nearly) all likeable, and have personality (and more camp than a scouts troop), different magical movesets, ever-growing powers, and there are even scenes where a group will have to take on tens if not hundreds of guys at once! There s no doubt in my mind that Fairy Tail would make an excellent crossover!

Make it happen, guys!

What games/shows do you think would benefit from this treatment?

The kingdom under fire game series would be a good fit for this or maybe Warhammer end times

5770377 A game like Dynasty Warriors or Samurai Warriors, eh? Hmmmmmmm.... Well, if there's any GAME series that would probably transfer well into that type, it would be the No More Heroes games. It would be simple: Have the playable characters be assassins that were either allies or bosses in the original games, while also throwing in a few new faces for uniqueness sake.

Now if we're talking anime.... I would immediately go for Kill la Kill. The potential is definitely there, what with everyone already having over-powered abilities due to Life-Fiber enhanced clothing, and given the number of nameless mooks who get blown about in the show in the first place, it's only obvious for it to belong in the same genre.

Although I guess the true question is this: Who would THAT game's version of Lu Bu or Oda Nobunaga be? The ONE character that everyone would be so terrified of that going up against them would be suicide?

I can kinda see Warhammer being done for this. Massive armies, Magic and the occasional giant stepping on someone.
Sounds about right.

5770377 I may be stretching it a little but given that most of the series is scripted like that how about code geass?

5776132 could work.

Also, it just occurred to me that Soul Calibur should do this too. It'd be kind of like the Tekken Force mode from Tekken 3, but better!