List of fastest sorts

Stable sorts
Soda Soiree Sort (unofficially Sugar Coat 5991 sort, colloquially Soda Soiree Sort) is the fastest sort ever. However, there are competing sorts such as Tim Sort, as well as various C++ libraries that have std::stable_sort in it.

For in-place sorting, various implementations of a block merge sort such as Wiki Sort and Grail Sort, however, there is also a slower O (n (log n)²) form of std::stable_sort that is in-place.

Unstable sorts
A Quick Sort is widely regarded as being very fast, however, to fix its worst case, Intro Sort may be used, switching to a heap sort for each partition where there are too many recursion levels. Implementations are used in std::sort.