My Vote goes to Mafft(insi) as it have ~86% accuracy and results in ~1.2 hour. Though fastest will be kalign takes only ~3 minutes to finish with an accuracy of 74.3%.
For each of the 218 reference alignments in the benchmark, we applied
eight alignment programs, resulting in a total of 1744 automatically
constructed MSAs. The overall quality of these automatic alignments
was measured using the Column Score (CS) described in Methods.
FIGURE 1: Overall alignment performance for each of the MSA programs tested.
(A) Overall Accuracy
(B) Total run time for constructing all alignments (a log10 scale is used for display purposes).
Source and Photo Credits:
A Comprehensive Benchmark Study of Multiple Sequence Alignment Methods: Current Challenges and Future Perspectives
PS: This is from an old paper of 2011. If you want the new statistics you can always test on your own, by the process described in the source paper.