Here's my list lol:
Love Hurts - Piper thinking she loses Leo is really sad
Deja Vu All Over Again - Andy getting killed and Prue crying, and when they're at his grave
Witch Trial - When Prue is crying because she feels guilty about losing Andy
Morality Bites - When Phoebe gets burnt and Prue and Piper are crying
P3 H20 - It's really sad looking at their mother's death, and Phoebe having to see it too
Awakened - When Prue and Phoebe think they lose Piper
Be Careful What You Witch For- When Prue gets killed
Magic Hour - When Leo blows up and Piper starts crying
Primrose Empath - It's sad to see Prue crying in pain
The Good, the Bad and the Cursed - When Phoebe is feeling what Bo is feeling
Just Harried - I was crying in happiness cos Piper finally got married, third time round
Death Takes a Halliwell - Prue crying
All Hell Breaks Loose - When Piper gets shot and Prue watches her die, and then gets killed herself
Charmed Again Part One - Prue's funeral, sob
Hell Hath No Fury - Piper crying really made me cry
A Paige From The Past - When Paige watches her foster parents die in a car accident
Long Live the Queen - At the end when Piper, Phoebe and Paige all snuggle up to each other
Sympathy for the Demon - When Phoebe 'kills' Paige and she is crying
Oh My Goddess Part Two - Again, Piper crying lol
Styx Feet Under - When Paige has to die, she cries and makes me cry
Witchness Protection - I didn't want Kira the Seer to die
Something Wicca This Way Goes - I thought it was the end of the Charmed Ones
Vaya Con Leos - When Piper has to lose Leo, again
Kill Billie Vol 2 - When Phoebe and Paige die, and Piper finds Phoebe dead
Forever Charmed - Last episode