Okay here's my final take, but please note that I dont have 5.1 sound on DVDs cuz stupid ass WinDVD doesnt support it with SB Live 5.1
Logitech z560 4.1s: Best sound of the bunch in my opinion, but some people like the Altec 641s better. The z560s definitely have the most bass punch and you can feel the rumble in your chest during movies. The highs arent as clear as the highs from the 641s but sometimes I felt like at loud volumes the high pitched sounds of the 641s hurt my ears. With the sound off and the volume knob cranked on the z560s there was very little hiss from the speakers, slightly less but about equivalent with the 641s. Overall the sound from these bad boys is powerful, punchy and full... Id give them five stars for gaming and movies, 4 stars for music.
Altec 641s: I said most of the stuff above.. but the nicest thing about this is the little wired remote... it feels solid and has tons of useful controls. If youre watching a DVD or something from 10' away you have control of the volume, which cant be said for the z560s. The speakers themselves are better looking and feel more solid than the z560s. The bass doesnt quite have the same rumble (I loooove the rumble of z560s) as the logitechs but definitely packs a punch. The sub weighs like 2039840932 pounds and is about the same size as the antec sx830 case. Clear, crisp highs, nice bass, and looks elegant. The perfect system in my opinion would be the z560 sub with the 641 satellites. 5 stars for music, 4 for gaming and movies.
Ok, that being said the above 2 sets are a significant step up from the Altec 241s and the Inspire 5300s, so its not really fair to compare all 4 directly. In every possible aspect the 641s/z560s are better than the 241s/5300s.
Altec 241s: This system puts out some quality sound (especially for $50 hellz yeah). In terms of volume its more than enough to fill your standard bedroom and maybe a small family room BUT the rear speakers just do not get loud enough... I felt like even if you maxed out the 'surround' knob then the rear speakers were at best equally as loud as the front speakers. Considering that with your typical computer speaker setup the front speakers are usually MUCH closer to you this could be a significant problem. The bass and overall sound I actually liked *slightly* better than the 5300s, but this system has one HUGE design error... Only the rear speakers are wall mountable because the morons that designed it put the volume/surround controls on the R front speaker, which means it has to be within reach of your keyboard. The speakers are really nice looking but Id have to give the edge in that category to the 5300s.
Creative Inspire 5300s: Overall a better set.. I initially didnt like the sound from them because I thought it was TOO high pitched and screechy at high volumes, but after a little bit of software tweaking in media player/winamp they sounded better than the Altecs. The bass is smoother but in my opinion slightly less powerful at baseline, but the overall sound is virtually equivalent to that of the 241s. The best thing about this set is that the volume and rear-front controls are on a wired remote (damn short wire but better than nothing). Both systems had a design error of having the subwoofer bass control on the subwoofer itself. In the end I think the Creatives are the set to get if youre choosing between the two, but you cant go wrong with either for $50.
Final conclusion: Get the z560s they rule.