What's a good, affordable sound system for my home?

Is a set of speakers for your computer a workable solution? If your computer is near where you would listen to music it might save you a few bucks.

If I were shopping for $200 speakers, I would get powered speakers that will play music from the Zune (or a computer as johnpowell suggested). And I would go with used.

Here are a couple of ideas:
Tivoli Model Two (add the separate Model Subwoofer for better sound)
ZVox 325

Try looking at the Logitech Model Line of powered sub-woofers and speakers meant for 5.1 theater installations.

Logitech x540’s. thats what i have. they are beautiful for listening to music. 5.1 surround sound. u can buy them for less than $100 on ebay. http://cgi.ebay.com/NEW-LOGITECH-X-540-X540-5-1ch-70W-RMS-SPEAKER-SYSTEM_W0QQitemZ220210371227QQcmdZViewItemQQptZPCA_Speakers?hash=item33458f9a9b

John’s right, you’d be surprised how good iTunes sounds when you slap on a sub woofer and a couple o’ satellite speakers. And those can be had for a song (pun intended!)

An alternative you might look at is to get wireless headphones. You could get a good set for a few hundred dollars.