South Ossetia, Abkhazia, Crimea . . . .
All three of those examples are to Russia's south, not to the west. South Ossetia and Abkhazia were struggling for independence from Georgia well before Russia countered and ceased NATO's meddling there in 2008. Those hardly qualify as conquests by Moscow.
Crimea is absolutely vital to Russia's strategic southern defense, and its seizure was a defensive reaction to the February coup in Kiev. We were dreaming to believe that Russia would allow its sole warm water port at Sevastopol and its surrounding air bases in Crimea to fall into NATO's hands. All that Russia's annexation of Crimea did was preserve the military status quo.
Since the collapse of the Soviet Union, NATO has added 12 new member nations in Central and Eastern Europe, and is now positioned along the borders of Russia itself. I'm still looking for any examples of Russia's westward expansion.