For EU4 (and CK2) the biggest native English-speaking youtubers with a high quality standard (good mic quality, excellent cutting and editing, loads of experience, steady content, decent articulation, excellent narration skills, good at speaking to an audience, ability to explain things, etc.) are certainly Shenryyr, quill18, and Arumba. They do dabble in other games as well, quill18 usually more so than the other two. But when it comes to Paradoxian grand strategy, you will be hard-pressed to find more consistent channels. Of course, all of them have their own quirks and caveats (from personal experience):
Shenryyr (California, USA) -- "sultry voice", shows the event log, usually rather methodical and strategic, often stubborn and occasionally "blind", probably older than the others but with childish tendencies (renaming provinces or CNs etc.), lots of "that's what she said" jokes, abrasive in tone at times, known to audibly burp and crack his knuckles
quill18 (Northern Ontario, Canada) -- quirky, "nice guy", cosmopolitan attitude, likes to explain things extensively, lots of experience with audiences, often has facecam up, methodical playstyle, at times indecisive and slow, well versed in historical background, strategic
Arumba (Florida, USA) -- ambitious, tech perfectionist (audio/video), quick robotic playstyle with hotkeys, likes to crunch numbers ad nauseam, excellent guides (especially for CK2), complains a lot about the game(s), usually impatient and prone to high-and-mighty attitudes, often easily distracted and oblivious to the historical greater picture, likes to play the "blame game", occasional iffy comments/undertones about women and gay people
Two more niche grand strategy youtubers worth mentioning are DDRJake ("part-time" feel, highest skill, exploitive and crazy, needlessly exaggerated voice at times) and MadDjinn (not as much content, likes to talk a lot and hear himself speak).
