Do you know Alejandro Dolina? His radio show archives can be found here in mp3 (downloadable) format: http://venganzasdelpasado.com.ar/
His shows are really interesting, educational, and funny.
My husband listens to him every single night while falling asleep (lucky me) and usually laughs his ass off every 5 mins.
The Spanish level is quite high (I don't understand it much if I don't concentrate reeeeeally hard) but great practice and a very high quality show!