Also during this book, the death and last words of Martel. Made sadder if one has read the Tamuli and knows that Martel was seduced into evil by his drive for supremacy rather than (initially) personal malice.
During the battle in book 5 of The Belgariad: when Doroon drowns. Rundorig says "He couldn't swim. I tried to save him ..."
In the same battle when the simple-minded nameless Arend peasant boy was sitting off towards the side of the battle playing his flute and is killed by a Mallorean soldier.
Also in that battle, when Brand's son who had earlier tried to kill Garion when he became the Rivan King told Brand what he had done as he was dying, and Brand turned on him in disgust.
The end of The Malloreon. Everyone is rejoicing and happy...and the Voice of the Prophecy, who has been present in Garion's mind for ten books now (ever since the start of The Belgariad) as a kind of Mentor/ Deadpan Snarker two in one combo, returns for a few moments to give Garion a So Proud of You speech, before dissapearing forever. Beldin and Vella's departure is also quite sad, as is Belgarath's eulogy for the last dragon.
Two from The Shining Ones. First, throughout the novel Sephrenia shows extreme loathing for the titular race and it is explained that she thought they were behind the murder of her family. Then it turns out to have been Zalasta, the man she's known for centuries as a true friend. He also tries to kill Aphrael, the goddess Sephrenia devoted her life to. Which ties into the second Tear Jerker- after failing to kill Aphrael directly, Zalasta has his minions in Eosia seek out the Styrics and kill Aphrael's worshippers. Styric gods are extremely devoted to their worshippers and they love them like family members, so seeing the normally playful Aphrael crying and declaring that "They're killing my children, Sephrenia! All over Eosia! The Elenes are killing my children! I want to die!" is enough to make anyone start crying.