I feel a bit different, but it is based on interest. I have played SotD and liked it alot. The gameplay became better as I got used to it. I own a copy of Vanquish, but have yet to play it, though I hear they do an outright good job, and I am getting Binary Domain for PC. I have no interest in Bayonetta.
It's just familiarity at this point, but boy are they both filling a vacuum in a western world whrere the fomulaic CoD and such series set the action/shooter bar. Even cover and more tactical based, in and of themselves get nothing but yawns these days. At least these 2 developers do bring on the crazy with varying levels of competence or rather, good gameplay. I suspect Platininum is ahead at the moment at least, there.
I love both of them for very different reasons. As a lot of people have already stated, Clover/Platinum has always put gameplay first in virtually all of their games and, in execution, that usually results in extremely refined experiences that, in my opinion, tend to come out on top among the best in class for their release year, if not that hardware generation. Granted, I think DS and Smash Bros.-esque Viewtiful Joe games and Madworld don't rank that high, but we all have our off days. In general, I tend to thoroughly enjoy their games; hell, I'm one of those people who would argue that Vanquish was actually a better shooter than what American studios put out that year. Some games like God Hand aren't necessarily designed for wide appeal, but the lingering quality in even those experiences shows just how flexible their talent is over there.
Grasshopper, on the other hand, tends to know style like few other developers out there. It does admittedly often come at the expense of accessible, well-thought gameplay (although I think the No More Heroes games are legitimately fun to play and made good use of the Wii remote), but usually what's there is perfectly functional and doesn't get in the way of the unique, distinctive atmosphere they churn up for their works. Suda 51 has pretty much always gone on record saying that he runs the studio as though it were a punk rock band and it shows; the games tend to be deliberately garish and lack a sense of refinement almost deliberately. It inevitably makes their works divisive, but that's as sure of a sign as any that the studio and their games have a real sense of identity and voice and that's still a surprisingly hard thing to find in this industry. It's not to say that Clover/Platinum games don't have their own distinct flair; if anything, it's only gotten more apparent, especially with Bayonetta. I just don't think they've ever gambled the prospects of their games on that in the way that Grasshopper consistently does, though.
When it comes down to it, though, it's got to go to Clover/Platinum. I think Grasshopper is a really important Japanese player, especially in terms of how to present more abstract narratives in a video game, but Clover/Platinum games tend to remind me on a very primal level why I fell in love with video games in the first place thanks in no small part to how well they usually play. I've never felt that they lagged "behind the times" in terms of gameplay and technology like some of their larger, more corporate Japanese brethren have.
I'll always be a little disappointed that Platinum ended up going in the direction that they did. I understand that they make really good games, but those games aren't really for me. I originally became interested in those guys because I loved Okami, and I was really hoping they'd end up making more in that vein. Granted, having made God Hand and the Viewtiful Joe games, I guess Clover always tended a little more toward madness. It's just not what I loved them for.