Some of them I don't even consider RPG. Dark Soul, Diablo and Deus Ex are RPGs?
Deus Ex is RPG, at least the first one. Big, sweeping story, customized skillsets and augmentations, story branching choices.
I understand you on the other two. Diablo has always been marketed as hack-n-slash RPG lite: heavy on the action, light on the RP aspects. Demon's Souls / Dark Souls is somewhere in the middle. On the surface it acts like a more methodical Diablo, but you do get much more character customization options.
There are arguments for and against many titles on the list. Like I said, Final Fantasy and Zelda play more like adventure games than RPGs and I like them both.
It was pretty deep for having been made in 1977. In fact, the character generation was unique in that you didn't just choose a character class, but you created your character by selecting professions and working at that profession for 5 years, then it would open up different career pathways (with different perks) based on socio-economic status, attribute scores or even previous career experience. Very cool!
This one often gets left off of reviews for some reason. It was the first one to copy the career-path character development of Oubliette. It was pretty interesting in that you were dropped into 15th century Germany during the Holy Roman Empire. The historical setting was interesting, and a refreshing break from purely fantasy worlds.