These games are all drastically different.
Quite.
Some place a lot more emphasis on story, others on action, others on more or fewer RPG-elements. What would your friend enjoy?
I can tell you which of those I enjoyed the most.
For setting and story, I don't think you can beat Morrowind.
For setting - though in a more austere way - and action, I'd favor Stalker. (Fallout - obviously - has a lot of similarities, but I enjoyed Stalker far more than Fallout. Fallout was fine, but I thought Stalker
intense.)
For something more like a table-top RPG, I'd go with KotOR (running a party, strong story and character elements, turn-based.)
As the best overall, I'd put forth The Witcher. Very strong RPG elements except for "party". As a fairly recent game it looks good. I liked the action. I thought the combat mechanics VERY awkward at first, but I got used it it and enjoyed it quite a bit by the time the first chapter was in full swing.
For all but KotOR, btw, I wouldn't be satisfied with the game un-modded. Err... but that'd go for almost every game on your list. I'll just mention that with Stalker you can get a mod that turns it into more of the desperate-survival game the devs. originally intended.
Re: Human Revolutions. I thought the story OK, though the game was more shooter than RPG, and really liked the character stuff in that you could pick and choose characteristics. Plus of course the game looked great. However: At one point, on a whim, I decided to try just blasting my way through a level full of heavily armed dudes *and it worked.* I couldn't maintain my interest in the game after that. I was already getting increasingly dissatisfied with how easy it was to sneak. IIRC I hadn't even invested much into either stealth or combat. I poked around for mods I thought might make the game more challenging but didn't find anything that worked.
SO: If what your friend would enjoy is a not-particularly-challenging game, but one that's extremely good-looking with slick-action game-play and ... err... I'm having flashbacks to this girl I went out with *once* in college. There are a lot of parallels between her and HR... err... I'm dropping the subject. Anyway: You've played the game, you should know if your friend would like it.
BTW - if you're into CRPGs you should try Vampire: the Masquerade - Bloodlines. Certainly one of the best CRPGs ever made. But it's got some flaws!
From wikipedia:
Kieron Gillen of Eurogamer admired the accomplished and "effortlessly intelligent" script, claiming that "no other game has come close. Nothing's even tried." However, he criticized the game for becoming repetitive in its final third, and for sporting a large amount of bugs on release.
The game has wonderful interactions with NPCs - full voice-acting, and they put some real care and money into it - a lot to do, a solid story, a hub-system for free-but-guided exploration, some very interesting set-piece missions, and great PC customization. The plot doesn't really *branch* except at the end, but not only will different characters have different ways of accomplishing things (stealth vs. combat vs. social, or whatever) but the way the NPCs act toward the character - and what they actually do - can vary a great deal based on both what the character has done and who the character is.).
The game, however, sort of falls apart into a combat grind toward the end. (I turned on "god mode" and just hurried through it to the conclusion.) You really need the third-party patches to fix those bugs.
I pulled out my copy not too long ago and played through it again. Uh, in fact it was right after I stopped playing Human Revolutions. I was in the mood for a good RPG and, for me, HR didn't deliver. Anyway - when I downloaded the patches I discovered there was still modding development going on. Some very elaborate stuff. So I think for some people no other game has supplanted Bloodlines - and surely not
all of them are goth-nerds.