I am gonna be slightly selfish and nominate the bit where Tsleeixth, Sadri, and Leif tag teamed to take down the captain of the Kamal vessel that assaulted them on their way back after retaking the dwarven ballistas. I liked how the three worked together, and I also liked how Tsleeixth's atronach pushed the captain into the water for the latter to drown. 

Honorable mention also goes to Sagax and Roze's suicide missions since those were always great.