Alright, here are my unpopular opinions:
1) Class balance is overrated at best and actively detrimental at worst.
2) While it has plentiful problems in the details, at a macro-level Hoard of the Dragon Queen is superbly crafted to introduce new players to the multiple methods and styles of play D&D can provide before tossing them into situations to put what they've learned into use.
3) "Barbarian" comes from the Ancient Greek term for "someone who doesn't speak Ancient Greek". Less an unpopular opinion and more a fun fact, this one.
4) The Star Wars Prequels excel at memes and absolutely nothing else. Yes, even Revenge of the Sith. I would rather re-watch Solo. Or Rise of Skywalker. Or hell, even just the first two acts of Rogue One.
5) By the by, the best Star Wars storytelling right now (I mean, outside of Andor, obvs) is happening in the Jedi games. I am hyped for Ahsoka though.
6) Against all odds, somehow Hawkeye, yes, Hawkeye has managed to be the best overall Marvel TV Show. Look, I don't know either, it just happened.
7) People who crap on "story games" either (a) have never played a "story game" properly and/or (b) aren't attracted to the core aesthetics of play of "story games" in the first place, and, critically, that's okay. Not every game has to be for them.
8) Apocalypse World is one of the least well-made Powered by the Apocalypse games.
9) The Ranger has never had an identity outside of "is Strider/Aragorn" and every attempt to stray from that idea to form a more fleshed-out identity has failed miserably.
10) Combat is the best part of Dungeons & Dragons
11) Combat is the worst part of Dungeons & Dragons.
12) No I will not elaborate, I feel both statements are self-evident.
13) Dungeon World got the balance between D&D and PbtA way off
14) D&D makes the best gateway RPG not because it's actually designed well for that purpose, but because it's the thing everyone has at least heard about and will bring them to the table to play until they either eventually grok the system or complain enough to let you pitch simpler, better games.
15) THAC0 and descending AC are both extremely counter-intuitive you absolute nerds and D&D is better off for moving to attack bonuses and ascending AC. Was it really that difficult? No, it wasn't that bad. Was it objectively worse than what we have now? Absolutely.
16) For a game all about combat D&D has never figured out a good way to properly use/scale HP. It's an absolutely mess; PCs either have too few or too many HPs, enemies always have too many HPs, there being absolutely no penalties losing any amount HP short of all of them, etc.
17) RPG campaigns are stories and stories need to have themes. If I'm taking the trouble of playing a character in a story I want it be about something
18) Say what you will about Rise of Skywalker, but the whole astral-projection lightsaber duel in the... I guess the first third act? or second second act?... anyway, is one of the coolest damn things I've ever seen in a Star War.
19) Character death almost always kills more dramatic tension than it causes. True in fiction and in TTRPGs.
20) Railroading gets a bad rap. Or I should say, people are way to quick to mislabel to the expectations of player buy-in as railroading.
21) The Wheel of Time show? Actually pretty good, for the most part.