Kohler is my favorite in the garden tractor field. The K series is rock solid, and long living, I have a Cub Cadet with a K241 that is over 40 years old.
Briggs hi
I'm with you i like briggs engines and kohler. I have a few Briggs the one i don't like to much is Briggs 20 hp els the air filter cover is right on top and when you open it up and if there is any grass clipping near by they fall right down in the carb and they are hard to get out again so once i have the cover off i put a clean rag in the carb intake hole so nothing fall in there while im look at the filter to see if i have to clean or change out with a new cleaned one. Other then that it very good engine.
It depends on it use. For riding mowers my favorites are Kohler & Kawasaki. For pushmowers & snowblowers its Tecumseh. The reason so many Tecumseh engines blow is due to how easy it is for homeowners to increase the RPM of the engine, there for overreving them for long periods of time.
I've only ever used a mower with a briggs and stratton engine, so a little biased, I have heard that honda engines are quite good.
Robin stationary engines are as good or better than Honda.