I remember one or two friendship flights involving F-15s visiting Russia and Russian fighters visiting either the US or Nato countries, but I really don't have any details or even the exact locations. I remember seeing a really nifty picture of either a Mig-29 or SU-27 painted up in airshow colors flying formation with some US fighters, and I vaguely recall the Russian fighter was over US territory.
But I don't have any details and it was a few years ago so I might be mis-remembering.