If you look at my signature line, you'll see I have more experience in outboards than most. Obviously, if you are in the USA, a new 4 stroke is your only option.
I've been an Evinrude / Johnson guy for over 50 years. In recent years I switched to 4-strokes on my every-day boats. I only have 4 at this point, and all are Mercurys.
In my home area we have about 15 outboard dealers. One sells Evinrude, One Yamaha, One Tohatsu and all the rest are Mercury. Obviously, that impacts my opinion somewhat.
I have had a Yami in the past, and it was a good motor. But the maintenance requirements were more than the others.
Bottom line is go with whatever your local dealer handles as long as you are happy with his service. If you have options, my recommendation would be a Merc. The performance, maintenance and ease of serviceability are simply second to none.