The most interesting trackers to me, for DIY install in my yard, is a 2-axis tracker. Especially in summer, sunrise and sunset are quite a bit north of east and west, meaning a true south facing fixed set of panels wouldn't even see the sun yet.

Sadly, my investigations a few years back indicated that a suitably strong and robust 2-axis tracker that would withstand our local winds and snow loads is significantly more expensive than just buying more panels and facing some of them east/south/west to accomplish the same thing. Doing this on an existing shed also avoids some local zoning rules vs a dedicated ground mounted system.