Define "best".
Since you're asking on EcoModder, I assume you mean best fuel economy.
If you're OK with 78 hp and 3 cylinders, the Mirage delivers very good real world mileage, and seems to have fewer quality/reliability issues than the Nissan (and a much longer warranty) despite its very light weight and "insubstantial" feeling. You can get a stripped base model for the same price as the Micra in Canada (10k before taxes/delivery).
The Mirage has revised brakes, suspension and steering for the 2017 model year that improved it quite a bit. The Micra hasn't changed since it was reintroduced here in 2014, but it is much better out of the box than the Mirage if handling/responsiveness is a main priority.
I assume you'd go with manual shift for the best fuel economy.
FYI:
http://ecomodder.com/forum/showthrea...-2l-29176.html
http://ecomodder.com/forum/showthrea...ost-32097.html
http://ecomodder.com/forum/showthrea...cra-30059.html
http://ecomodder.com/forum/showthrea...age-27384.html