Ask anyone what the best 8-bit wrestling game is and most will say Pro Wrestling by Nintendo on the NES. From Star Man to Fighter Hayabusa, Pro Wrestling was where it was at in the 8-bit days. Sega had some decent wrestling titles but well, the Master System sold like crap and no one remembers those. Inginuitive fans have hacked Pro Wrestling and created WWE Wrestling.
What we have here is a pretty interesting hack, one that I would have thought was done years ago. Apparently the wrestler graphics are stored weirdly in the ROM so it was not as easy as simply swapping graphics out for new ones. The ring, title screen and wrestler names have been changed making this a total conversion of Pro Wrestling.
Pro Wrestling is not freeware so we cannot link to a download for that but we can link to the patch file over on ROMHacking.net
For more on Pro Wrestling, check out issue #2 of Retro Gaming Magazine.