My speakers have just about 'given up the ghost'. What brand (very inexpensive) do you recommend?
Hmm.. For the computer or for a stereo?
This is a toughie really.. I don't have any brands I can recommend, for all sorts of reasons -- it depends on what you want. All computer speakers nowadays generally are powered by USB cords, and all of them are fairly small and cheap and not good quality, even the very expensive ones are normally so-so.
But that's just fine if you don't care about that, are mortifying yourself, being practical et all.
If you're looking for higher or average+ quality sound, you connect the Mac/PC to a stereo and run it through that, rather than just buying speakers themselves. That's the way you go.