We're RPG player, we have a long tradition of trolling each others, AD&D player will tell that Vampire is the opposite of a RPG while WOD player will reply that AD&D is a boardgames and that it misses the role play element to be called RPG.

But all this trolling tend to be all fun, and not many people would straight up refuse D&D game (even I, play it like once a decade, there is so many other game out there and so few time)

Without saying anything negative about D&D 5e, let me tell you about two of my personal favorites:

The Dark Eye

Under the name "Das Schwarze Auge", this is one of the most popular systems in Germany and has existed since the mid 80s and the latest edition has been available in English for about a decade now. There are dozens of source books and hundreds of official campaigns and standalone adventures, all set in the same world and a single ongoing canon (apart from a few early works that have been retconned). There are decades of detailed in-world history that you can use as a background for your own campaign if you want or selectively ignore if you want to focus on your own interpretation of what the world should look like.

Mechanics-wise it's a lot less board-game-like than some 70s/80s/90s systems while not going the full "storytelling first" route that many more moderns systems seem to prefer. On top of the eight basic attributes, characters can select from a pool of skills and feats that cover everything from combat to magic to social interaction to crafts and hobbies. The system focuses a lot less on combat than other high fantasy systems and it's absolutely viable to have a group of purely social-focused characters that never get into a single fight but still get to use a lot of the system's mechanics.

Overall it's relatively complex if you want to use absolutely every rule but at the same time very versatile and can be customized to your playstyle.

Opus Anima / Opus Anima Investigation

Sadly out of print and never officially translated to English so I'll focus on the one thing that works without the official setting: it's one of the simplest systems I've ever seen. It uses a pool of D2s (odd/even on D6, coins, red/black cards, whatever you have on hand) where the number of dice is determined by a basic attribute and a skill that can be combined however the situation requires. Dexterity + mechanics to build something, perception + mechanics to recognize a mechanism, knowledge + mechanics to understand the underlying principles or remember who invented something. To avoid experienced characters failing an easy check out of pure bad luck, everything over 10 dice is not rolled but gives half a success (rounded up) automatically. That's it. That's the whole system.

Yes! Thank you!

One Roll Engine is my obsessive small-time RPG system. I've always loved systems where you get to roll a heap of d10s, but more importantly it has a highly expressive and generalizable core mechanic that allows everyone to roll at once without taking turns, and attacks resolve in a dynamic fashion so that initiative order, damage, hit location, and contested rolls all happen in one roll. It's great for gritty, fast-paced, lethal combats where you can give players a lot of freedom to get creative and stay engaged. It has great rules for easily killed mooks as well, so you can quite easily have huge numbers of enemies and allies all in one battle, and it takes far less time to resolve each turn - and a far greater proportion of that time is people talking about what they're going to do. Reign uses ORE, and that includes rules for running companies (gangs, businesses, armies, entire countries even). I've used ORE variants to run occult horror, mecha, low-magic fantasy, slice of life, robot sci-fi, and more over the years. It's a great system and I can teach 85% of what you need to play in just a few minutes.

The thing is that if you don’t like it, you can modify it. If it’s better, the people you play with will be cool too.

I was recently introduced to Death in Space.

Things that I like about it:

• it's a simple system
• it's got cool lore (the universe is dying, aberrations are infiltrating the local solar system, all ships and technology is scavenged)
• it's got some overlapping mechanics with 5e, which makes introducing it simple (advantage, d20 checks, etc)
• it's got some nice rules for ship combat, space walks, etc
• combat turns are basically just go next if you have something, then the enemies do their thing, and players coordinate on whatever works best for them

My fiancé was running it, but lost the time to continue running it. I might take over with my own group soon.