You can play CDXL video on a 68000. It's uncompressed, so it depends more on the speed of your drive than anything else. If you're playing it from a CF card, you should be able to get decent sized HAM6 CDXL videos playing on your screen. You'll need to download some CDXL playing software from Aminet, and scour some CDTV/CD32 discs for some videos, or you can make your own by converting MPEG/AVI videos.
You can also use a program to convert your MP3s to WAV or IFF 8SVX, then you can play them in SongPlayer or one of the other music players, and it will sound as good as Paula can sound, but won't be CPU intensive to play.
The files all end up being larger and lower quality than the original compressed formats, but the fact that you CAN make a computer from 1985 play full-motion video (in 4,096 colours) and fully digitised songs is still pretty impressive.