StudioPress has probably one of the best options for premium themes. Not to mention air-tight security, built in SEO settings and a huge developer community always keeping everything up-to-date.
Desktop Serverpress has helped me speed up my develop time tremendously. It makes setting up a local WordPress environment a breeze! Great for dealing with setting up multiple websites quickly.
Beaver Builder in my opinion is the best WordPress page builder I've used. Especially if you like doing a lot of custom styling yourself. It makes laying out a WP page incredibly easy. Not sure? They offer a free trial.