If you like this opera, and ever get into DVDs, I highly recommend this production.
I love Boris but have never listened to Khovanschina, so I must seek it out now. You see Clayton, your finances are not the only ones threatened by threads like this one.
Never try to teach a pig to sing. You will waste your time and you will annoy the pig.
I don't know much about Russian opera but I do like Aleko
Since this thread was started Rubinstein's The Demon has entered my list in the top 5, and Prince Igor has shot up as well. Also Karetnikov's Till Eulenspiegel is in there somewhere.
#1 is Boris Godunov (Mussorgsky orchestration, both 1869 and 1872)
Also like Khovanshchina and Iolanta.
Haven't experienced any others--yet.
There are no long Wagner operas. Only short attention spans.