Best for mostRobin Hard · 2014
Robin Hard's Oxford translation is the one I'd start with — and notably it's a complete modern English Discourses, with the Handbook and fragments included. Clear and faithful, with Christopher Gill's introduction. This is where I'd start.
EpictetusDiscoursestr. George Long
The free classicGeorge Long · 1890
George Long's 19th-century translation (and Elizabeth Carter's older one) are public domain and free — including the famous Handbook opening, 'Some things are in our power and others are not.' Dated English, but free and complete.