I'm a fan of Pi-hole and Uptime Kuma, as both work incredibly well after the first deployment. Vaultwarden is another gem that I never had to worry about after I began using it instead of a paid password manager.

Resource-heavy tools like NextCloud and Paperless-ngx need frequent tweaks to work correctly. I use them in combination with Immich for photos, but I cannot call them “deploy once and forget” tools.