There's been a lot of discussion about whether combat in RPGs is good or not, but I couldn't find a recent thread with suggestions for good combat systems.
For me, The Witcher 2 is definitely up there, mixing a good blend of action and flashiness with a good amount of realism and difficulty.
On the turn based side, I really like The Last Remnant and Resonance of Fate's systems, both really deep and require a high level of understanding, but it's really satisfying when you get them down. Special mention to the Fire Emblem series too, although that's less of an RPG in the traditional sense.
So, which RPGs do you think have the best combat systems?