I bought a heavy chisel type device from Home depot that is really for chiseling through Ice.
Its very heavy and resembles a log splitter on the end of a garden shovel handle. However its thinner and straight. Easily sharpens to perfection on a bench grinder but don't make it too sharp or you will end up planing the sub floor. I removed my entire kitchen floor in minutes. What ever you use be sure to use hearing protection, a mask and eye protection. Its loud.