harmonic waves are totally cool. the crest of the largest one I ever helped make managed to fill the nearby hot pool with luke warm water. the ladies weren't too pleased.
I was at a water park in colorado once. They had a wave pool there that was shaped like a mushroom. The wave would come down the stem part and into the half-circle part, bounce off the rounded wall and converge back in the middle with about a 10-12 foot spike of water. Fun place to stand.