What’s your favorite engine mount?
The one that comes with the chassis.
Which chassis come with an engine mount? That would be a good list to have.
As far as best, I guess you need to set some criteria to judge them by? Weight? Convenience? Strength?
Personally I’m not fussy, but the nicely machined ones by Odenhal and Burris etc do look 
Any engine mount that makes adjusting chain tension less of a pain is a win in my book.
Is there any reason on the degrees? How does the 0, 5, 10 degree mount impact the engine or chassis?
I guess that’s more my question. What do you find important is it a certain angle, a mount style, material or something as simple as cost that makes one better to you.
We run a 5 degree on our KA. I wouldn’t run any less than that simply because the chain could then hit the top portion of the clutch guard.
I am fat…I chose the OTK magnesium mount cause it was light. I believe the theory on angled mounts for aired cooled engines is it allows a little more airflow to hit the rear portions of the head (cooling fins) allowing it to cool better. The KA is soo tall that any angled mount just means you hit your elbow harder on the damn thing when you hit a bump.
The higher angles like 10 and 15 are aimed at four stroke OHV engines to help the air filter/carb clear the rear wheel.