Small Office Multimedia Speakers?

BiLlCaT asks: "I am looking to buy a nice set of speakers for my PC in my new office. I want something that will sound excellent, yet maintain a small package. I am also looking to get the most "bang" for my buck. I have two scenerios to pose; one, where i have $250 to spend and the other, i have $500 to spend. Any ideas? "