My first love is still the strongest. In fact, nothing has been as musically pleasant for me as that "awkward" moment when I realize I'm listening to something by Tchaikovsky that I had never heard before, just by the sound of it. Unfortunately, I've almost run out of compositions from him (so I'm already digging deeply into his operas in search of it).
BTW, I tended to reject opera at first, so the fact that I was able to turn myself into an opera-lover could easily fit into this topic. I dare to say that this transformation was possible due to just two masterpieces: Bizet's Carmen and Tchaikovsky's Eugene Onegin. But the ones who made the sell were Tchaikovsky's Queen of Spades and Puccini's Tosca. Too bad I haven't still learned to fully swallow Wagner.