I'd say Fallout 4 with no doubt, I tried the beta for Battlefront, got bored real fast, and it's not like they can actually add completely new missions/maps/etc. as there's stories/etc. to be followed from the star wars, and if they don't come with new content eventually I don't think it'll live long. Fallout 4 has a good amount of neat easter eggs, references to other stuff, personally I love the new setup for the power armour although fusion cores will be a pain once I spend the twenty I got now/etc.
The only downside I see to Fallout 4 at the moment is bugs and the chances of finding spoilers, only had some minor bugs and the rest will probably be patched rather fast.
Save your game frequently in Fallout 4, a small amount of people has had issues where several files saves went corrupt, although reloading five to seven saves earlier fixed it. :tuna:
Not to mention there's already a new nude female body for Fallout 4.