To date, my favorite has been the YouTuber AllofPokemonTCG.

Yes, his biggest videos are huge, 4 hour hoard openings, but he fits a few of my criteria:

1. Good voice/temperament, doesn't overreact, his surprise seems genuine

2. Decent knowledge of various sets

3. Pronounces names correctly! Maybe this is pedantic of me, but I really love Pokemon and I feel that anyone who is investing the money and opening hundreds of packs should learn the names.

4. Video quality/setup is good

5. Doesn't take TOO much time opening the packs, but you also get to see the art as well. Some folks spend way too much time on each card and gushing over EX pulls, and some fly through cards so quickly you don't get to appreciate the art on commons and uncommons.

So there it is! For even more reference, my absolute least favorite is UnlistedLeaf. I know he gets tons of views and has great production quality, but he just makes me cringe a little with how over the top he gets with some things.