Not quite sure. 3 is definitely out, immediately. I bought it despite the fact I knew I'd be disappointed - which made me feel less disappointed about it, but nontheless :P
The setting in 1 is actually the best, but 2 fixed a lot of broken stuff (like most of the weapon types being weak, or too many skills being useless), but also weakened the mood. Still, I think I prefer F2, all in all, although I miss some of the atmo of F1.

I like the gameplay in 3, it is different then 1 and 2 but the game world and atmosphere is very much "fallout." The VATS System adds a lot of tactical thinking to the equation. The only thing I didn't care much for is the level cap, but that is being raised soon.
Which one do I prefer? Hmm. I like all of the games for different reasons and that includes Fallout Tactics. I really can't pick and will just have to say I prefer all of them ;)

Fallout 3 is just so different game that i find it impossible to even try to compare it to it's predecessors. It's good in it's own way, but not nearly as good as Fallout 1 or 2. Sorry Bethesda, but "much to learn you still have"

See I don't agree: I think Fallout 3 is as good of a game as the previous ones..and I've played them to death.
Ah well, different strokes for different folks I suppose ;)

Don't get me wrong, I loved Fallout 3. Played it for more then 100 hours and enjoyed every minute of it. But for me it doesn't have that great atmosphere that previous games had. And there are two things that make Fallout 3 worst game then F1 & 2. Pathetic main quest (I mean they got many brilliant quests and the main story shallow as a puddle. What were they thinking?) and terrible dialogues.
But as you said. It's a matter of opinion.

I didn't think the main quest was any more shallow the fallout 1 and there was some bad dialog in that game as well. I just think fallout 1 and 2 had issues that are rarely discussed that were a detriment to the game...but he games as a whole surpassed that , just like Fallout 3.
And I thought they nailed the atmosphere in fallout 3 myself, heh. *shrugs*

Use Games for Windows Live for any Fallout 3 DLC.

and if you live in the rest of the world (read not in USA) then you are fucked up. Not that i wanted to play anchorage (i can buy short shooter much cheaper), but dawn of war 2 requies GFWL too.

Even if I lived in a country supported by GFWL i would't buy anything from them. Sorry, not from Microsoft for stupid points.

I don't know, but my sence for service in name of emperor-god was stronger than my hate against microsoft (i even bought vista due to my 8GB RAM) but there will be many games that i wont buy due to GFWL. Same with steam, rather I buy boxed game than steam version (not only for its crazy pricing)

What of you get a boxed game that requires a Steam activation? Then what?
I bought an indie game in the box and all that and then I saw the insidious STEAM logo on the back and bottom of the box and the text of evil "Requires a Steam account to activate product". AARRRRGGGGHH!

I have steam, so it doesn't matter, i am used to it, at least they have nice weekend deals.
But i don't see usefullness in GFWL, why should i run two programs just to play some game? to be honest, DoW2 is maybe first and last game with GFWL that i bought.

Meh, they all have their ups and downs. I find that the 1 & 2 are a bit tedious and a bit drawn out at times, but has the overall best story and characters; Tactics is good at what it does: a party based ARPG. with lots of stat heavy combat; 3 is good as well, with what has become Bethsoft's trademark CS (or GECK in this case), even without mods I enjoyed it quite a lot, but it does got a bet boring and tedious after a while without any.
Right now I'm playing 1 & 3. With 1 I'm only using a unofficial patch of some kind, while with 3 I'm using a few major gameplay overhauls, which adds more monsters, weapons, stuff, puts a lot more emphasis on stats and skills, and reworks balancing to make it more challenging.

to be honest, i started F3 yesterday too, with FOOK and some more mods modifiing game to be more "falloutlike"