I'm looking for a change of pace from RPGs and want a fast paced action game. It's got to be single player, I don't have the internet reliability or speed to play online. Something that comes to mind just as an example of the type of game I'm looking for is something along the lines of Ninja Gaiden Black, not necessarily a swords game but just something with the same high pace and intensity.

The only game that I can think of that fits what you want and I'm not sure if your computer can handle this game but The Witcher 2 comes to mind. You don't need internet if you get the GOG version of the game.

Left for Dead?

Something like Bleed perhaps?

Wut?

Absolutely godawful game for single-player alone.

Agreed. In multiplayer, it's absolutely glorious, but playing with bots is fairly awful.

The new Devil May Cry game is supposed to be quite decent. It's got a lot in common with the NG games.