Depends if you want to feel the room shake or not. You want a full surround system or just something that's better than TV speakers that you will eventually add to later, potentially spending another $600+ to fill it out?
$200 is not really enough for a full system. Cheapest I'd ever want to go for full system is something like:
http://www.thespeakercompany.com/PLCR161-HT8-P102C36.aspx for $280. (For this one, extra center you can't use since receiver is 5.1). More money would be better, more options.
If $200 is just for the front two, and you can live without much bass below 50-65 hz, there are lots of choices.
