Promedia 2.1 would be my 2nd choice, they are very well known and touted as the best 2.1 speaker system you can buy, and have been for damn near a decade. You really can't go wrong with these for the price range. Sub hits hard. Klipsch puts out some of the best home audio equipment there is.
1st choice would have to be Logitech Z-5500 THX-Certified 5.1
They are on amazon for $839 which is fucking outrageous since they originally retailed for $400, they have been discontinued but are still very highly sought after, which is the reason for the price hike.
You can snag a "like new" set in the link I gave for $280 shipped, which is just under your price range.
I normally don't fuck with Logitech speakers but these are in a league of their own.