Before I make recommendations, here are some general thigs about speakers for PC's:
- you should look for as much diaphragm area as you can get - meaning that you want to move air. To move air, you need diaphragms. Funny little speakers with tiny silver diaphragms may look good, but technically, they are crap. So what you want is a properly-sized 2-way-speaker (tweeter and mid-woofer) or a sub-sat-system (tweeter & midrange plus subwoofer)
- forget surround sound for normal applications. It'll only make soft- and hardware setup more complicated, increase costs and screw up the sound. For music, you want a good set of stereo speakers, probably accompanied by a small subwoofer
- forget fancy marketing phrases such as "500 watts", "THX-certified" and the likes. Almost every speaker you buy for your PC will have enough power, and everything beyond 50 Watts is a lie anyway. THX once meant something, but it has been broken down to many different forms to make you buy the THX-licensed speaker. But the one next to it may be just as good, maybe better. A THX-speaker can still be good, but that logo is no guarantee
So here's my recommendation: for a good allround PC speaker system, I'd get the
Klipsch ProMedia 2.1
https://pic.armedcats.net/a/an/anonymous/2008/12/12/pm21-1.jpg
It's a proper subwoofer-satellite-system that fulfils all needs, definitely one of the best 2.1 systems you can get for your PC. I had a bit of trouble finding new ones on the market, so you may have to look around a bit. I found some dealers selling fully tested display models or returns for around $100. That's a fair deal I think.
P.S.: Yes, I know these are THX-certified, but they are good speakers anyway.