I've noticed that you can tell a lot about a Fallout game by the first town you come across (after the intro area)
In Fallout 2, there's Klamath. Klamath oozes personality with every character you meet. It has every type of quest you'll find, and gives you a strong impression of the social commentary for the game (with how you meet Sulik). It has impossible fights that you can stumble into, and in a word is fun but not fair.
In Fallout 3 there's Megaton. Megaton has interesting side stories that you barely interact with (i.e. Simms and Moriarty's dispute, the slow expansion of a town built originally by religious zealots into a commercial hub), and a few simple quests. The combat area nearby (Springvale) also seems to have stories that you aren't a part of, and none of the combat is terribly difficult, and all quests (but Wasteland Survival Guide) can be done quickly at any level. Finally, there's the game's morality be a saviour, or a monster, no middle ground.
In New Vegas, there's Primm (with the NCR Outpost being a secondary part of the location). Simple combat, some of which can be skipped, a story that revolves around you making the important decision for the people living there instead of them making their own damn decisions, and a traditional Western theme of Civilization vs. Frontier.
In Fallout 4 there's Concord. You get to here about a sad story in the past, introduction to the settlement mechanic at the end, and POWER ARMOR MINIGUN, giving you the strongest things you'll see in the game, but with terrible upgrades to show you the importance of the upgrade system.
Hbomberguy talked about something called play conditioning in his video about Bloodbourne, and I find the way the Fallout games condition you to think about each of them through their first town fascinating.