Tallima: The Realms of Arkania games should be very detailed if they're anything like Drakensang. They use the same rules, but I haven't played them, so I don't want to assume anything.
Realms of Arkania is actually more detailed, even though Drakensang is based on the much more complex 4th edition of the pen&paper RPG "Das Schwarze Auge" (the dark eye), while Realms of Arkania is based on an older edition.
The reason for this is that the developers of Realms of Arkania incorporated far more skills and spells from the pen&paper game. Unfortunately, this results in some skills/spells that have almost no purpose at all. There actually is one spell that seemingly can not be used at any point in the game. And another one that is only usable in two places in all three games. If I remember correctly, they should be called Summon Ghosts and Banish Ghosts.
I don't really know about Fallout 2, but Fallout 1 also had it's share of pointless stats. For example, Science is a total waste of points, likewise Charisma, but Agility is God.
To be a bit more constructive: I think, most games based on Dungeons&Dragons 3rd edition (Neverwinter Nights, Temple of Elemental Evil, Icewind Dale II) have quite detailed character creation and development. The only exception is, I think, Pool of Radiance.
Wizardry 6-8 are great too: 6 and 7 are very luck-based, but there are lots of different races and classes and you have the option to change classes. (In 6 and 7 you should use it. A lot.) This allows you, for example, to create a warrior that uses stealth, a priest that wears heavy armour and stuff like that. Too bad those are not on GOG. You might try ebay for finding "The Ultimate Wizardry Archives" (which contains parts 1-7), but stay away from Wizardry Gold! This is just Wizardry 7 with better graphics and a lot more bugs.
Wizards & Warriors (NOT the game for Nintendo ;) ) also has a good character system, sort of an improved version of Wizardry 6/7, but you have to get past a couple of bugs and general awkwardness.
Oh yes, and Arcanum! And Star Wars: Knights of the old Republic I+II, very D&D-like.