Features of best sorting algorithm

The ideal sorting algorithm would have the following properties:

• Stable: Equal keys aren't reordered.
• Operates in place, requiring O(1) extra space.
• Worst-case O(n·lg(n)) key comparisons.
• Worst-case O(n) swaps.
• Adaptive: Speeds up to O(n) when data is nearly sorted or when there are few unique keys.