In my opinion, of the first-person Fallouts, they should be played sequentially. While you won't find any sort of satisfying house-building in fallout 3, the world available for exploration is one of my favorites. read more
Fallout 4 is the only game of the bunch that includes building houses(bases), gun modifications and a decent story (even tho fallout 3 and NV both have a diffrent but good story). In my opinion you should start with Fallout 3, just to see how much has changed compared to Fallout 4. read more