Gboard all the way.
Amazing auto correction (it's really smart), tons of easy editing features (slide on the spacebar, slide left from the backspace -- once you learn these tricks, editing is a breeze), gesture-typing for quicker typing, especially during one hand usage (you can also justify the keyboard left/right if you prefer to thumb tap with one hand), and a decent array of settings/customizations you can do (including changing keyboard theme, height, and numbers row).
Gboard also incorporates Google search right in the suggestion bar. It comes in handy.
Try it. It's free. And it rocks. Leagues above any other smartphone keyboard.