Not much I'm afraid. Japan doesn't like the PC as a gaming platform as much as we do here, and usually only develops a few genres that never leave the country (by which I mean H-games).
That being said, they do exist. Here's a few off the top of my head, all fairly old (I haven't been keepin up with PC releases much I'm afraid):
Grandia 2 was a port of the Dreamcast RPG, and it a pretty solid-if really short- game. Decent graphics, good sound and voice acting, and it's available pretty cheaply.
Oni was an anime-styled game made by the same lot that did Halo (Rockstar handled the PS2 version, whic is why it's on their site). It's not the greatest game ever, but it is pretty entertaining for what it is. Also available on the cheap.
Shogo: MAD was another western-developed, anime-styled game with giant robots and a great sense of humour. Sadly they decided to release it around the same time as a certain Half-Life and it vanished without a trace. It's a great game a) if you can find it and, b) can find a system it'll run on.
There are also a couple of free games by indie Japanese developers that really need a shout:
Perfect Cherry Blossom: Magical girl curtain fire game. It's easier than it looks, honest.
ABA Games: Staying on the mad arcade shooter theme, ABA has a couple of gems. rRootage and Torus Trooper are recomended, and are among the "purest" games you'll ever play.
Warmning Forever: Last shooter, I swear. This one has your tiny ship facing off agains an endless parade of bosses, each bigger than the last, that adapts to the way you play.
Nanaca Crash: I'm sure this one has done the rounds already, but it deserves andother shot. With characters from the H-game Cross Channel, the aim is to hit some poor sod with a bike and get him as far as possible.
There are others out there, but these are the ones from the top of my head. There are also mods and character models for existing games that give them an anime slant, as well as a growning number of Korean games with a really similar style. Give em a shot, see how you like em.