Currently there are many 4.1 PC speaker sets on the market in the sub-$300 price range. Many of them are good, but IMO there are only two "really good" sets. The Klipsch PM 4.1 and the BostonAcoustics BA4800.
Both will play clearly at uncomfortably loud volume levels, but the Klipsch have much better clarity in the upper ranges due to the satellites being a 2-way system (separate midrange driver and tweeter) versus the BA's single-driver design.
If I'm not mistaken, the BA's come with floor stands for the rear speakers. Dinky little stands that dont' raise the speakers high enough off the floor IMO, but the Klipsch don't come w/ANY stands. So score one for the BA's there.
Depending on how desperately you want a "perfect circle of sound" around you, some creative engineering is needed to mount the Klipsch sattelites. Email me me if you want and I'll email you some pics. Personally, I dislike having speakers in the middle of the floor. I'm clumsy and would crush them in 2 minutes flat. 😱
Both sets are great. Depending on how critical your ear is and what sound good to you, you can't go wrong w/either one. I have the 4.1's and have never heard anything like them. Using my machine at work with the dinky little $10 pc speakers is quite depressing at this point. Good luck.