Successful application of branch-and-bound methods for NP-hard problems
For TSP, checkout this book...
http://www.tsp.gatech.edu/book/index.html

My understanding is that there is no one tool to kill them all. Arguably any recursive solution deploying backtracking and some scoring function is using branch and bound. As such, a large fraction of solvers to NP hard problems use some form of branch and bound.