Walletgenerator.net... hmmm is that the one where the website was "sold" and then after it was sold there were numerous claims of scams and "already used" keys being created?
Or was it another one?
No, Bitcoin Paper Wallet.com was sold and turned into a scam. Wallet Generator.net shouldn't be trusted either, for reasons mentioned
by TryNinja.
The only one then is bitadress.org?
That's the only site I trust, but even then, I only use a version I've downloaded years ago. This way I don't have to trust they don't change something.
Still a warning though: check the URL! A typo could lead you to a phishing site.
Don't use any website to generate your paper wallet.
That works too
Your only "advantage" literally is that it looks pretty when printed.
I still have an old copy of Bitcoin Paper Wallet (currently a scam site!), and it allows to import a private key. You can even combine a split key vanity address to use 2 different random generators so you don't have to rely on just one of them being honest, then import it, and print it. It creates the same pretty print, without having to trust them. Of course, all this should happen off-line (and it was a big hassle getting my new printer to work without connecting to the internet).