Castles & Crusades is still one of my go-to fantasy games. It feels just like classic AD&D, but with many modern improvements to simplify the game to play from 3x5 cards. I don't need any 5E-like OSR games; while they are fun, they don't do it all like C&C does - while still feeling like a classic experience.
It is a mix between 3E and 2E that feels right, and so many of the "charts needed to play" simply do not exist in this game - you don't need them. You have a character card and 90% of what you need to know. If you want to unify the target numbers, set them all to 18 and give +6 to primaries.
The 5E OSR clones (Shadowdark, Low Fantasy Gaming, and a few others) strip the experience down and try to provide the OSR experience through a 5E lens, which is fantastic. Those games have beautiful art and are real collector's items, but another part of me feels I have been down the niche OSR and 5E road a few times. I am not really feeling the excitement for Shadowdark, it looks fantastic, but I have shelves full of amazing OSR games I never play. I wish Shadowdark the best and hope they become a de-facto 5E OSR-style experience for many.
I have a lot of OSR games I like much better, and I have too many of them to play.
Old School Essentials does everything OSR and more, with the only difference being mechanics. I am not playing OSE, but this still stays on my shelves since it is such an incredible experience and set of rules. I can see why someone would prefer Shadowdark over OSE; infravision proliferation exists in every fantasy race except humans and halflings. There comes the point in 5E and a lot of games where "easy" takes over, and everyone wants to see in the dark, and then the referee has to account for some races having 60' or 90' ranges, and no one picks humans or non-night vision races because "who wants to be carrying torches around?"
The Shadowdark game addresses this fatal flaw and makes light sources a part of the game, which touches on our fears of the dark and that primal instinct. I like that game designers are starting to recognize this D&D problem and address it with their designs. The fear of the dark is a powerful force, and to see it marginalized in games takes away a considerable part of the fear and unknown when exploring dungeons. It doesn't help when so many races in 5E have night vision and light sources get factored out of the game.
Low Fantasy Gaming does the 5E-style grimdark experience very well, and it also addresses the night vision issue by giving no races this ability. I love LFG's take on feats since you get to make the powers and abilities up yourself (with GM approval), and every character is unique. This game also tackles many of the 5E gripes and fixes them through pools and mechanics. LFG also has many exciting classes and powers, with this "savage survival" feeling that appeals to me more than stock 5E or Shadowdark and focuses on the wilderness and exploration along with dungeons. They renamed the spells, which is annoying and cool, but I get why they did it so I can play along.
These days, I look for longevity and publisher support in a game, and I love feeling. The Shadowdark game hits those notes, but I like LFG for my 5E-style old-school games, just for the gritty feeling and innovative mechanics. Whereas Shadowdark leans more toward the OSR and even games like Lion & Dragon, LFG leans in the direction of Cypher System and even Warhammer.
The mind-blowing Appendix N game with dangerous magic and incredible feats of heroism? Dungeon Crawl Classics is my best-in-class game for that. This is OSR gaming at its finest, with all sorts of strange dice and nothing ever being the same twice. DCC is another S-Tier game for me. I am not currently playing this, but just for inspiration alone, the game is incredible.
I am currently out of the market for random OSR games and taking stock after the January OGL disaster. Many games are abandoning the OGL, which is a good thing. The next one I am looking forward to is ACKS 2 since that game fills a Middle Ages niche that I love from a historical and 4X kingdom-building point of view. ACKS has a darkness and uniqueness that sets it apart from many of the AD&D clones, and the conflict against the "Conan-style old world" and the "civilized forthcoming new world" sets the stage for everything that comes after.
Work is continuing on ACKS 2 to remove the OGL from the game, and what I have seen so far is incredible. The game is going from a B/X-style game to its own standalone game. This gives me the same feeling OSE Advanced has; the game moved away from its B/X roots to become something of its own game with its own identity.
But I keep coming back to C&C. There are a lot of flash and hot games out there, new mechanics, and some beautiful art in the newer games. I keep returning to something stable, where everyone is welcome, and the game feels like the familiar one I grew up with. I don't want a lot of complex rules, so I am stepping off the Pathfinder 2 releases for now. I don't have the time or the group to play that. Also, many of the newer PF 2 releases do not speak to me; they feel pop-culture and anime-influenced, which is not what I look for in a dungeon game. They are fine, but not for me.
Castles & Crusades is one of my S-Tier games, quickly replacing Pathfinder 1e since it does everything much more manageably and cleaner than a 3.5-era set of rules. The options and multi-class features are the absolute best in the OSR, giving you so much flexibility in creating characters that it blows my mind. Multi-classing is so much better in C&C than 5E, and this is the old-school style where you can level up both classes simultaneously, not pick and choose levels.
Playing off a 3x5 card without having to open a book feels the most like old-school gaming, and C&C does that wonderfully while still keeping the feeling of AD&D at the table, but with a modernized and streamlined flow of play.