You could try Dark sun: Shattered Lands or Dark sun 2. Not the greatest graphics but not terrible.

Definately Drakensang and Drakensang 2. No better old school RPG's out there. Divine Divinity and Lioneheart: Legacy of the Crusader are great if you're looking for something older. Real gems, much better then a lot of what usually ends up on the "greatest RPG's ever" list.

If you liked Deus Ex you'll probably like Human Revolution too.

And if you don't mind somewhat poor graphics in a new game Driftmoon is well worth attention. It's a very charming, old school RPG, a little short but has a very fun story, great cast of characters and a lot of heart. You can tell that it was made by people who know and love the genre.

Despite of what others suggested and unfortunate it is not here:

Albion

Nice RPG, nice story, nice complex.

And for its time really nice graphics, mixture of 3d and 2d....

have a look at it!

http://en.wikipedia.org/wiki/Albion_%28video_game%29

IIRC it is even freely available, please correct me, if I am wrong ;)

I did purchase it orginally and I enjoyed many hours of it!!!!

http://web.archive.org/web/20010210101021/www.bluebyte.com/us/products/albion/p_details.htm

I'm really enjoying it. It took me about 5 false starts before I got the hang of how to play it, but now I'm on my way. It's got such a great atmosphere and lots of individual little touches I really like. When it comes to RPGs I like dark, brooding atmospheres and in-depth mysterious storylines so it's right up my street! Reminds me of when I first played Fallout.

I do have to say that you seem to have great taste in RPGs.
I have only played a bit of Arcanum, but it seemed to go nicely with your list.
I will also second some of the games that were mentioned: Ultima VII and Gothic. Mount & Blade I also enjoy, but is different.

I only wish that Black Isle and Troika would get together and have babies. :-)

I will take a better look at Anachronox. It kind of got a bad reputation from that Ion Storm fiasco. Deus Ex made it, Daikatana didn't. Anachronox got kind of mixed reviews.

Try bioshock. Spiritual successor to system shock. But DRM-ridden, and steam exclusive. If that does not make you puke, then you can give it a try.

You can also try the new Deus Ex: Human Revolution.

And of course, the witcher series. Witcher 3 is said to be open like an elder scrolls title. That aside, this series is great, how come it is not already mentioned in your played list?

I´m also surprised about the witcher series..
I´ve just finished the first one and it´s one of the best RPG´s I´ve ever played.

i'll add another vote for Arcanum. I played it for the first time last year and it surprised me. combat can be broken if you abuse it. it does so many other things so well though. in some ways it felt way more open than other isometric rpgs I've played.

I really recommend Anachranox. I'm not a huge fan of the jrpg style combat, but it's an excellent game. Genuinely very funny but dark and moving too.

Realms of Arkania - most sophistiicated. (user-unfriendly)
Arcanum: Steamworks of Might & Magic - most sophisticated (user-friendly)

Note with RoA that you'll have to use the included hint guide (especially for finding your way around town) I've edit the games conf file so I can keep the game in a large enough window and still easily swap back and forth between the game and Adobe Reader for the guide.

So much fun! That is great! I also recommend the geneforge series. And I've played more of Inquisitor now and have to recommend it if you like dark and brooding. It plays more like an action RPG as far as combat and character skill development goes (think diablo), but it is not weak like diablo in any regard (other than fluidity of combat animation) - everything else is different and superior. To me it is as if someone played diablo and felt how weaksauce it was in terms of being an RPG and did it all "right." Great story, atmosphere, characters, writing, and roleplaying ability is uniquely implemented. I've never had so much fun NOT choosing the "good" or "evil" path and playing it by the situation and not caring where it ends me up because what matters at the moment is the moment. I've also never played an RPG where upon doing a series of quests/related quests did I look forward so much to going back to someone I've already talked to 5 times to talk to them AGAIN to progress the story. And never have I made so much effort to delay as long as possible in finishing quests, because the longer I wait the more there is to be revealed. The best word I can use is "driving."

Inquisitor sounds great! I'll give that a try, although I've been distracted by NEO Scavenger now too!

I wouldn't take recommendations of this f**king loser, you might catch something.

Arcanum
Arcanum
Arcanum
Arcanum
And I almost forgot:Arcanum.