The easiest quick way for me to find the markets for any token is just to check coinmarketcap's token page> Markets tab. So for Waves:
https://coinmarketcap.com/currencies/waves/#markets. If it's not on there, then the numbers aren't significant enough anyway.
As you can see, it looks pretty extensive, but of course as others point out, there's not much action going on outside of Tidex, which has got more than half of the Waves volume. The Waves DEX itself together runs up quite a bit of volume, and is slowly picking up. Yobit also as mentioned has a few pairs trading (released some months back along with Doge and LTC, if you can believe).
I'd recommend its own DEX if you want to get Waves, simplest and probably best priced.