Ooohhh. Gen V music huh? IMPOSSIBLE for me to name just one...:
B/W opening sequence theme (where N is crowned as king), B/W Title theme, Accumula Town, Gym Leader's last Pokemon (which must come back to S/M imo), Route 2, Route 10, Route 11, Route 23, N's Final Battle, Ns farewell, N's encounter theme, N's b2/w2 encounter theme, N's room... N's B2/W2 battle, BW Credits, Cynthia's theme, Alder's encounter theme, Entralink, Kanto Gym Leader theme, Johto Gym Leader theme, Kanto Champion theme, Johto Champion theme, Hugh's theme, Three Musketeers/Forces of Nature theme, Dragonspiral Tower, Relic Castle, Ghetsis' Theme, Colress' theme, PWT final battle, Team Plasma's theme, Neo Team Plasma's theme,
But if I had a gun to my head, B2/W2's title theme. That is the epitome of a masterpiece - the powerful horns about 30 seconds in, then cutting to the calming instruments about halfway in reverting then back to the thunderous horns at the end, gives me a feeling I can't even describe. It's a very "triumphant" theme.
I have high hopes for Sun/Moon after hearing the themes so far, though. Looks like it is following in the steps of Gen V's music. Is the composer of Gen V music doing Gen VII's too? I can definitely hear similarities.