(This has probably been discussed a lot in the past, but I only started Fallout 3 recently.) I like some of the unexpected events that are possible in Bethesda games as well as other games like Stalker:SOC. A couple that happened to me this past week:

A robot started shooting at my character in the wasteland but was taken down by a yao guai. I had chosen the Animal Friend perk only a few minutes before, but it was good to see it kicking in already.

The android-rescuing woman West talked to my character for the first time and gave him the android component. Unfortunately my character was in the minefield town at the time and West walked off into the houses to her death. At least I was able to salvage a key from her.

What are some of the random events you've experienced in the vanilla Fallout 3 game?

... suddenly a deathclaw came and killed me.

Well, I found two scavengers fighting over a fridge in the wasteland.

Entering Dukovs "palace" with the surrounding area's serene as a post apocalyptic city can be. Then BAM, I walk outside and the place is crawling with Enclave with " Tame" Dealthclaw.

I found the Wanderer the other day. He was unfriendly, but his dogs were not. I don't have Animal Friend. I've been coming across wastelanders being chased by various rodents like a Deathclaw and a Giant Radscorpion. If I save them, they give me maps to various spots.

The guy in between the alley, He has loads of mines and mini nukes ready to blow up.

Well, one time I was walking down a road and I happened upon a Raider-made molerat race track.

And another time I found 2 raiders playing baseball on a baseball field. It was one raider running around the bases holding a bat and one raider on the pitcher's mound. Killed them both and there were balls all over the field and another bat against the fence.

In the GOTY version I found.

Random fights between animals and robots.

Freddie Gomezs corpse sliding down from a hill.

I killed Dukov and Cherry and Fantasia ran outside and got chased by mirelurks.

They ran back and some mirelurks killed them in the door.

There have been random Enclave soldiers appearing early in the game.

One appearred by Dukovs place a lot this time.

Oddest thong I've come across
Somebody had cleared the mines on the bridge leading to the Anchorage War Memorial
Then when I get to the AWM theres 4 raiders beating up another guy whos in his underwear only hes a raider too and attacks me when I try to rescue him :shrug;

That's one of the random encounters. It's an initiation ritual, the guy in the underwear is trying to become a Raider.

I also found 4 people stood round a fridge in the wasteland.

A ghoul, a wastelander, a scavenger and another raider.

They attacked when I came in view.

I killed them.

It had a load of stimpacks in it.

I also found a baseball field with baseball stuff in it.

It did not look prewar. It looked like someone just finished playing.

I may have also seen two raiders playing baseball.

But they attacked me as soon as they saw me so I did not see much of their game, lol.

It was the first time I played it and I rampaged through the game killing everything I could before it killed me.

And I did not know about stealth much at the time.