KLH 970A Main / Stereo Speaker

These were available new for under $30 and I originally purchased them for rear speakers for a surround-sound system. I quickly found they could handle more muscle than that and now use them for a older stereo in another room. Considering their size, these things 'rock', providing a full range of music and are able to reproduce music accurately at loud volumes. Not "tinny" or "squeaky" like other small speaker systems, they actually have a tiny little bass port in the rear. Heavy-duty speaker wire push-button clamps are more serious than on some more expensive varieties of speakers.
Another great feature is the variety of mounting options. It's got little adhesive rubber 'feet' you can place on them and there's also mounting hardware included that offers a pivoting mount for accurate imaging.
Who knows? With a cheap subwoofer, you may have a pretty believable full-range system for close to nothing. These would be great for any application: restaurants, porches, beaches, whatever you could think of.
The best part is getting the reaction.... "Wow! I had no idea that was coming from those little speakers!". It's happened more than once. I'm sold.