As much as I loved Septerra Core, the 30 to 50 turn based battles you had to go through just to get from Point A to Point B really started to become tiresome. It was the story that kept me going though that.

The action in Divine Divinity was mostly hack-and-slash because the skills and monsters were unbalanced. In Diablo II you did have to think stratagy sometimes. You couldn't afford to be surrounded, even as a Barbarian. As anything less, you had to make damn sure that you weren't going to get overwhelmed at any one time. You had to keep the monsters at bay and spend your mana wisely.

Try Castle of the Winds and see what you think of single-character, turn-based RPGing: http://vengeance.et.tudelft.nl/cow/
Note: This site offers both part 1 and 2 of the game. Part 1 is shareware. Part 2 is a comercial release, not shareware, so it is technically breach of licence to download this without purchasing it. But I'll leave your morals up to you.