mine was when i saw rex get mauled by 5 deathclaws and i just managed to escape, i was really upset . another one was when i saved just as a deathclaw was about to strike, not good!

New Vegas
Sad: when I had to kill Benny for Caesar, I always liked him despite shooting me in the face.
Mad: Cazadors, nuff said
Fallout 3
Sad: when Liberty Prime died
Mad: when Liberty Prime died

Cazadors. I hate cazadors with a passion.

Starting out NV, running down the area with the Deathclaws that leads to the strip. At first I thought I could take them, started out with anger went to sadness then to a mixture of both followed by happiness.. best hour and a half of my life.

@LordEdwardius
I've got some news for you:

Benny Returns - http://www.nexusmods.com/newvegas/mods/44776/?
Liberty Prime Companion (in NV!) - http://www.nexusmods.com/newvegas/mods/43222/?

On topic, it was pretty damn sad when ED-E sacrificed himself in Lonesome Road, I really felt bad for it.

Sad:

Spoiler:

Mad:Trying to clear deathclaw promontory

When I tried to kill Deathclaws at Quarry Junction, I got killed a lot even though I had high-leveled armor. Then I realized that a Deathclaw's attack ignored my DT/DR. That is when I got really angry.

The first time Dogmeat was killed...I really felt the pain From that day on I started to sent him to wait outside Vault 101, unless he was essential via console/GECK.

My angry moment would be Cazadors just...never liked them for some reasons and and trying to get to the strip as fast as i can terribly armed and a little to cocky and getting mauled by Deathclaws in 10 seconds haha. My saddest moment would be seeing those kids chasing a rat for food and all you can do to help is kill it nothing else and seeing my trust robo dog Rex get mauled by Deathclaws,Cazadors etc.

Dogmeat getting killed. One of my first mods was one to set him essential, I was not on board with losing him.

Mine was at Quarry Junction when I had to clear the deathclaws. I succeeded the first time, but wanted a screenshot with the mother deathclaw. I guessed which button was the screenshot button(f12) and accidentally reloaded to my last save. It took three more tries to redo what i did the first time.

Fallout 3
sad moment: fallout 3 epilogue (cut scene after activating the memorial)
mad moment: carrying all mothership zeta loot to safe house

New Vegas:
sad moment: Killing Gabe in Old world blues (i recently knew i can save him)
mad moment: missing mesh or messed texture, that is a nightmare !

Lets see. lets see, ah, in Fallout 3 My Sad moment was when

Spoiler:

died. My Mad moment was not realizing that the switch to the door for Pinkertons lab was

Spoiler:

.

In Fallout NV, the maddest I've been was when I was playing the game back when it came out originally on 360 and I was at the battle of the Dam not realizing I couldn't go back and tie up some loose ends, just as I had done in FO3 before starting the purifier, effectively making me restart my whole character over.

The saddest was when, well I never felt sad over anything in that game, well I guess leaving

Spoiler:

was it for me.

Saddest moment was listen to Boones story, enough said..

In fallout new vegas : sad :I have to destroy Hidden Valley for caesar's legion with no choice whereas I don't want to kill them
mad : Try to recover the enclave power armor in the deathclaw promontory, that was very hard

For Fallout 3, My saddest moment is pretty cliche, But still has to be mentioned.

Spoliers:

Maddest moment was having to put up with Sticky.

For New Vegas, Saddest moment, For me was...

Spoilers:

My maddest moment was figuring out...

Spoilers:

I think one of the most tragic was in Dead Money when you realize that Christine was Veronica's aforementioned girlfriend. Haha, I had even had Veronica with me using mods. I'm like, "She's right there! Go to her!".

I saw a simular thread on gamefaqs and I think that this post is really sad..

''I was going to red rock canyon and I saw some bighorners, so I decided to snipe them (didn't know they don't attack you)

I felt like a total huntsman when I saw their bodies on the ground, but then a little baby bighorn comes lonely as the only survivor, poking one of the bodies''

Link to thread:

My mad moment is every single f*****g time I have to enter Vault 22, I HATE THAT VAULT!
Go down, door is blocked, go up, take that passwod (in the meanwhile destroy an entire flora and fauna), then go again down and take the pieces that Paladin Lorenzo want for the ventilation sistem, then save that woman ghoul (kill even more flora and fauna) then go back on the Labs floor, take the files, then you have to go down once again and burn everything, then go again up and talk another time with her... AHHHHHH!!!

My sad moment is when you merge Dog and God personalities and when you got to know that Christine will remain in the Villa, I always feel sorry for both of them... Christine instead of going back to the Brotherhood she decide to remain there, in total loneliness... and God/Dog that wake up in a ghost city inside a ghost casinò... that DLC leave to me a lot of melancholy.

Watching Liam Neeson (Dad) die in Fallout 3 was probably my saddest moment in the Fallout games. I thought he would be going on until the end of the game but then he just died.