The ominous "Korriban, The Homeworld" depicts the dark yet mighty feel of the Sith's homeworld. In addition to the sinister and ominous theme song for the Sith Inquisitor.
"Tython, The Wellspring" has the feeling of mystery and serenity surrounding the Jedi's ancient homeworld.
The epic march-like music of "Balmorra, The Forge", the heavenly part of the song near the end is also awesome as well. "The Occupation of Balmorra" is another track that has many great parts throughout, such as the catchy battle music for the Sith Empire in addition to the epic Ominous Latin Chanting of Revan's theme near the end.
Final Duel, the theme used for most of the class storylines' Final Boss and other similarly climactic showdowns, such as Darth Malgus in the False Emperor Flashpoint.