I'd always argue for Linux Mint Debian Edition, especially for noobs. Regular Mint is fine too, but they have not announced its future as far as I know. What with Ubuntu going all in on snaps and all that. Personally I think they should just make LMDE the default Mint and call it a day. Let Mint 21.3 be the last version and then go all in on the debian base.

I always point people to PopOS. Like Ubuntu and Fedora, it is backed by a company meaning there are dedicated developers who are paid to work on it. System76 also makes hardware for normal humans so it is tailored for the average person.

The thing about suggesting distros is we are inclined to tell people all the options. I say use PopOS and don't give them any other choices. Has worked well for me so far.

Vanilla just means they have no ideas about changing anything. It may be good to not duplicate effords or annoy Desktop developers. But its not really something crazy great

I think Debian is great for servers but for desktop use for casual/new Linux users it's not the best, IMO. The install ISO can lack drivers (one with non-free drivers is available but hard to find), the installer is not great (although I heard it's gotten better since I last tried), non-free packages are not in the repos, packages are stable but that can also be out of date. It is vanilla but I don't think it's the best UX.

I think Debian derivatives are easier to sell like Mint, PopOS, maybe Ubuntu (yeah, yeah snaps/malware/etc.). If they're a bit on the techy side maybe EndeavorOS just because Arch Wiki and AUR are pretty sweet. If they're 13 and wear hoodies Kali ;P

But it all depends on the use case right. If I set up a laptop for my Mom and she only surfs the Web and uses a word processor and it just needs to be reliable and not break on updates, I think Debian is great for that. But for someone that wants to explore a bit or has to install it themselves I think there's better options.

Also I feel that 'help my Debian is having $issue' vs 'help my Mint/PopOS/Ubuntu is having $issue' is going to bring up different styles of answers. Debian forums or articles may expect a level of competence that is not expected for distros often recommended to beginners.

Please define what you mean by vanilla.

For people who want a desktop, I either tell them to install it themselves or go for LMDE if they don't really care as much. But I wouldn't voluntarily use Debian, I don't like distributions running Systemd