You basically described Baldur's gate 2.
You can solo the game with Sorceror for example. Or get a party.
Although you get to do lot of quests, it's very combat based imo.
You have lots of unique artefacts and tweaking to do. Dragons to defeat etc.
Story is fun, and starts pretty fast.
You can look stuff up on GameBanshee or so for some minor guidance with party, areas, etc.
You can fight real-time or pause if you have too much on your hands.
You get magic right away from the beginning. And not just basic magic, you start with first 4 levels of magic.
You can create insanely powerful Fighter/Mage and thrash stuff like Hammerdin on steroids.
You have troll invasion on one stronghold in the beginning there, so there, goblins
*end of advertisment*
Or you can try little forgotten Icewind Dale + Icewind Dale 2. Gothic/Gothic 2 also very good.