My all-time favorite PC games (excluding text genre and rogue-like games) were Civilization and Masters of Orion. Both turn-based strategy games. Oh, and Diablo II. I'm not up on what's current because the descent into real-time strategy created disinterest.
You might like FFX then. Well done and pretty linear. It had just enough side quests (that were not required) to give you the illusion of non linearity.
Oh heck yeah.
During exam week in college my soph year, I had exempted a couple of exams which allowed me a day off....I spent over 16 hours straight on my roomie's 386 playing that game again and again and again....
Medieval: Total War is interesting.
It's part turn-based part real-time. You play out the strategic parts on a world map with not time restrictions, then switch to another map to fight the battles in real time (although you can pause).