1 - Fallout 2 : A Post-Nuclear Role Playing game - 100/20
My favorite game, even outside Fallout franchise.
It is very similar with Fo1, on many aspects, but is also unique, amongs the games i played, mainly in how they blended constant satire & references into a setting that make sense and is interesting. It reminds me a lot Candide from Voltaire.
Also, it has more things to do, more places to see, more quests, more npcs to talk to. It improves reputation system and followers, and have incredible dialogs depending of you good and poor stats. (it is awesome to see the dialogs options for characters that have low-brain, low-charisma or poor sexual skills)
You are the chosen one, and yet, the game makes fun of it in every ways.
It also has the best cities in the franchise (New Reno, Broken Hills, Vault City, San Francisco, The Den...)
PS: It is also my first entry in the Fallout universe.
2 - Fallout 1 : A Post-Nuclear Role Playing game - 80/20
One of my favorite games as well. Share many features with Fo2, in a more limited gameworld.
It has a better main plot, a better antagonist faction, and a gritty feeling.
Compared to the master & the unity, many factions and antagonists feel underwhelming.
It also seems very faithfull to dev original intents.
3 - Fallout New Vegas - 18/20
A.K.A the real Fallout 3.
It is awesome that we finally got a satisfying third game, after 10 years and three disapointing entries in the Fallout universe.
It came at a time when a faithfull sequel was unexpected.
It managed to even be better than my expectations for a Fallout sequel.
It improved the C&C, the alternate endings mechanics, the reputation system, the average quality of followers, it brought back some factions forgotten since Fallout 1, if gives the best insight into the Unity, since Fallout 1 & Broken Hills. It also add new cult characters in the franchise.
On the other hands, since Fallout 3 made me sick of generic continuous game world full of generic locations, i tend to feel very hexausted in visiting all these useless places, full of disapointement. I know that in following playthrough, i won't visit them any more, but still...
Also, it lack some of the option (and humor) of Fallout 2, that i greatly miss. I am not sure upcoming games will have them someday, but still, FONV is a faithfull sequel.
At last, i preferred when i could play Fallout in TB with my mouse alone. (Also, i am not sure you could do a satisfying complete pacifist run)
4 - Fallout Tactics : Brotherhood of Steel - 14/20
Underrated Gem.
I was kind of disapointed that the third entry of the series wasn't an RPG, and i still thinks FOT would have benefited from a few more dialogs options.
Also, it have some crippling inconsistencies and some story-arc (Beastlords, Reavers, three way-war between BOS, Calculator's army, Super-mutant/Reavers) needed to be extended, the plots are quite short, but in the end, i think the overall experience was fitting with the Fallout Universe, and is quite faithfull to the original tone. (far more than Fo3)
It improve combat system, include the choices between RT & TB, include the vertical scale, more vehicles, gives some very good insight about the BOS & the militaries, and is one of the best games on the tactical genre.
But still, i can't put it higher than Fallout RPG.
5 - Fallout 3 - 5/20
It brings a continuous gameworld, it has open-world wide open sandbox GTA-like features, the scenery is beatiful, things that not everyone like and are side features to consider for a Fallout game.
Other than that ?
Poor quality of writting, lack of dialogs, lack of actual NPC, inconsistencies within the fallout universe, internal inconsistencies (without even considering it as a Fallout, the game contradict himself), illogical stuff, the lack of C&C, lack of replayability, the quantity over quality, decrease of the grey morality, inability to pick sides, the Bethesda vision about provided more sceneries to see instead of more things to do, the overload of "generic" contents instead of "unique" contents, the lack of cities, factions, the fact that people didn't recovered in 200 years. The Bethesda vision that is the complete opposite of the original dev vision.
For instance, the way the original dev depicted their hate for "chosen one" characters in Fo2, is completly forgotten in Fo3, as you play an actual chosen by destiny character. The grey morality is replaced by good samaritans in white armors agains't mass murderer in black armors... The ghouls & super-mutants were people struggling to be accepted and became monsters to shoot. The list is endless.
In the end, the actual games look more a way to show their hate for the Fallout Universe than an additionnal entries into it.
6 - Fallout: Brotherhood Of Steel - 3/20
I don't think it is more awfull than Fallout 3, but i give credits to Bethesda to have made an ambitious game in their own twisted way, while FoBOS feels like more lazy.