What makes an armoured cruiser the best?

What was the best armoured cruiser ever built?

Scharnhorst is a strong candidate, depending on the standard used and how well a design met its contemporary requirements.

The German Scharnhorst class is a tempting choice, although strong American and British contenders remain. The word best first needs a defined measure. One useful criterion is how well a ship met the requirements and standards of its own time. That approach keeps a favourite isolated performance figure from overwhelming the design's intended mission and historical setting.