Any space considerations? If not, going with something like a party speaker will be best for hard thumping movies and music. You'll lose some of the clarity and overall sound quality that all of us on this forum treasure, but if these arent your primary considerations, don't worry about it. Here are some recommendations:
If size is a consideration, get a computer speaker system. Klipsch and Logitech make systems that will go thump and are around your price range (Klipsch has the better sub).
Check BestBuy.com for:
Wharfedale Zaldek 600
JBL Northridge N28
Athena Technologies AS-B1:
Not your best thump speaker but BY FAR the nicest here (and probably the
nicest near this price point).
Check CircuitCity.com for:
Pioneer SH253BK
Polk R15 (more in the category of the Athena, but go with Athena if it comes down to it)