We have a number of options here for you to consider, but keep in mind that by posting your question, we're also hoping that our dear readers weigh in with suggestions as well.
As for a recommendation, we suggest starting with CNET's reviews to find the system that will work best with what you're looking to have and what you're willing to give up. Keep in mind that sales can bring the price into your budget, so don't be afraid to take a glance at items that are a bit pricier than your top end budget.
If you find a system you like but it's not wireless, consider the $100 Rocketfish Universal Wireless Rear Speaker Kit to make the rear speakers wireless. Another option is the LG Wireless Speaker Kit for Home Theater, on sale for under $100. Keep in mind that there are plenty of systems out there that have wireless rear speakers, so these are only for certain circumstances.
If you can't find the right wireless set up, you can at least go minimal with a sound bar; the link goes to a guide put together by Gizmodo. They recommend the ZVOX ($200-$600) for eerie surround-sound like effect, which has a cult-following (and pictured at the top of the post).
Technology is improving all the time in the faux-surround-sound category, so you'll be able to find options in your price range. Another option Gizmodo recommends is the Yamaha YAS-70, for its compact nature.
Hope this helps you find what you're looking for!
- Image from Gizmodo.