I have a roughly 300 sq feet Apartment (20' x 15') and 8 feet high, and a Pioneer 5070. I don't want anything TOO loud, but would like a little extra oomph instead of the TV speakers. I'm in a relatively quiet apartment complex, so I'm not really looking to blast the neighbors into the next galaxy.

Also, I probably don't want to spend $500, and I'm looking for VALUE (so if I can get away with a couple hundred bucks somehow, all the better).

What should I get? How's the Logitech z5500? Is that a good deal? Thanks.

Man, I don't know about the Logitech. Nice for a pc, but not for your rig. Going cheap and flimsy is just not the thing to do. If I absolutely had to go cheap, I'd probably try 3 pairs of these in/outs from Insignia

http://www.bestbuy.com/site/olspage.jsp?skuId=7314523&type=product&id=1118843685964
or a little more:
http://www.bestbuy.com/site/olspage.jsp?skuId=7682769&type=product&id=1138083502985

and $175 for a Velo VX10 sub.

For around $450, Athena Micra is even better. Search eBay for the micra to see.
If you have be light on the $$, you won't be out much. Otherwise, you're in cheap HTIB territory

You have a nice TV how about nice speakers. http://www.aperionaudio.com/product/Intimus422Harmony,12,35,17.aspx

If I have to go cheap, I would hit the polks when its on sale at frys or go fluance.

http://www.fluance.com/fluan5speaks.html

Here is some reviews:
http://forum.ecoustics.com/bbs/messages/3/14778.html
http://reviews.cnet.com/surround-speaker-systems/fluance-sx-htb/4505-7868_7-21114465.html

Check http://www.jr.com good prices like frys

Get good speakers to go with your tv. Just because you could rattle your neighbors window doesn't mean you have to. They will sound better and you'll be happy with them for a long while.