Open the link I posted above, go to "Alexander Govorov's Choir," and click on "Lord, by Thy strength... By Bortnyanskiy." I absolutely love it. To me, that's an epitome of Eastern Slavic church music, a brilliant piece of the 18-th century Ukrainian Rococo, the culture that gave the world St. Paisius Velichkovsky, St. John of Tobol'sk (the great-great-...great-uncle of St. John Maksymovych), and many others... And it's a Paschal hymn, too.
Not to disagree but I must!
My preference has always been for the older, simpler chant forms - prostopinije or znamennyj. The Baroque era and the 19th century Russians like Kedrov, etc. with complex harmonies and/or polyphonic singing just don't do it for me. Give me a congregation singing plainchant or just a single cantor chanting monophonically any day.