some times ago I had a lot of business trips around Russia..
What do you want to see?
In Russia there are cities which called "Golden Ring" (Suzdal, Vladimir, Yaroslavl, Sergiev Pasad (near Moscow and beautiful place!!!!) ALSO New Jerusalim (in Istra!!!!! My favorite place). A lot of churches, old buildings and history.

There is Kaliningrad. but this is more Europe than real Russia.

I like Murmansk!! North, polar night/day, and sea/ocean