I like Russian folk metal because it has a distinctive spirit and melody to it, but it is hard to find something that stands out, nowadays. But Rvi Mekha has a very fresh music, really great rhythm, kind of a "disco-like" jumpy vibe to the songs, and great vocals paired up with lovely bass, and of course - the garmoshka :)
It is hard to choose a favourite song, sometimes it is Letavica, sometimes Tayna Lesa, sometimes Za Rechkoju :)