I chose option 1, but like a fella earlier, that was purely cos it was closest to my opinion, it was not how I actually feel.
Fallout 1 and 2 were two of the best RPGs I have ever played and I found them so good they've made me snobby about any other RPG I've played in future. Fallout 3 was always going to be a hefty mantle to take up regardless of whatever company bought the rights to it after Interplay collapsed.
Now, while I don't dislike 3, I've played it many many times and enjoyed it often, I always found it a) hideously buggy, but that's due to Bethesda's horrendous use of the Oblivion engine, seriously, anyone else I've seen use the parts of the engine (like the Havock engine for physics) have used it well, Bethesda just suck at their engine and NEVER EVER BLOODY PLAYTEST and b) lacking in comparison to the previous two, which is a massive shame as newer tech surely means that it shouldn't lack, it should build upon as all sequels should anyway. Fallout 2 was genuinely huge and to this day I've never done everything possible, and then there's also the Restoration Patch which adds a ton more.
The previous titles had a greater sense of immersion and depth than 3, which wasn't exactly helped by only having around 5 people of each type, be it Raider, Citizen, Bro Hood and so on, as well as the still appalingly low amount of voice actors (I'm not saying here you should have an entire score of people, but seriously, they used about 8, and then Liam Neeson, who is win).
But in the end there was just so much more to Fallout 1 and 2, and personally I feel it was a daft decision to not have any cult references in cos they were the basis of many jokes and other things in the classics (You can use one of Darth Vader's lines to intimidate someone at a point in 2) while there were more options to do things instead of just guns blazing/sneaky/diplomatic which is the result of most of Fallout 3's predicaments. The older games just felt warmer, more in depth and just more plain fun than 3 did. It also had a FAR darker atmosphere about it which added to it.
Fallout 3 was also very easy, few times did I die and that was usually cos I fell off one of the bridges

Fallout 2 was massively hard by comparison and was challenging. the combat system was more tactical in 1 and 2 as well with a bit of luck chucked in for good measure, while in three its mostly trying to shoot baddies around walls and doors with absurdly huge hitboxes (That is, the walls and doors were far bigger than they looked. Also, WHY CAN I NOT CROUCH UNDER STUFF?)
Fallout 3 was still fun, however, just not as fun as 2, maybe on a par with 1
Fallout New Vegas, however, was in between 2 and 3, while still not being as good as 2, it was loads better than 3
EDIT: Oh yes, almost forgot (reading other posts and being reminded 4tw ^^), fucking acceptability nowadays, christ I wanted to shoot the children in Little Lamplight, so I did and found them invincible, which was excruciatingly annoying, I didn't try it at the time, but I doubt "slay" in console would have killed 'em either. (At one point it bugged out anyway and randomly completed the quest without me realising, so I had to turn no clip on to get through the gate that you had to open to complete the quest ¬¬) which you could do in 1 and 2 (admittedly in Europe the "guidance" was just starting to kick in so you had to grab a patch from America, but hey ho, all fixed. And you gained a negative trait for it. But I'm basically going back to my concluding statement anyway, that the older ones were more in depth and better :/
Also, it had far more gameplay. People nowadays ><