Do you consider high quality sound to be important, and do you plan to hookup four to 5 speakers to your computer, If you answer yes to both questions, get a PCI soundcard to go with it. Either The SoundBlaster Live 5.1 series or the Philips Acoustic series will do. (Hint, if you plan on upgrading to XP, get the soundblaster series, as this is the most supported for this OS, if you stick with 98/ME, either card will do. If you are not a highquality sound guy, and the current sound has served you enough, wait awhile for the prices to go down and stick with your integrated solution.
If it works for you then don't fix it.