I am still very new to PICO-8 and saw a few games rendered with polygons.
This lead me to the Trifill Thunderdome benchmark by Musurca.
One thing this benchmark didn't show was the number of tokens for each method which is an important detail considering the limitations of the platform.
Also, I wrote two triangle rasterizers in 163 and 335 tokens respectively which perform pretty decently. They might be an acceptable alternative to ElectricGryphon's super fast triangle rasterizer if you need an extra 2-400 tokens. If you don't, by all mean use his. It is the fastest one I found, and by a good margin!
Update 20180706: Added the possibility to switch rasterizer and turn the test triangle with the arrow keys. This allows to compare rasterizers at a normal pace. Updated EG's rasterizer to the latest he posted in the previous thread and added the one from Gryphon 3D Engine Library v2 only modified to use normal color() and fillp().
Update 20180708: Added a fill pattern and a toggle for the results and control wireframe.
Hope this helps,