Barozi on 05 June 2015
well considering you're hyped for the upcoming Fallout 4, you should start with Fallout 3 (my personal favourite game of all time).
Fallout 1, 2 and Tactics are made by a different developer who invented the IP. Bethesda then bought the rights.
Also it would be better to get the Broken Steel DLC for Fallout 3 (if you don't already have the GOTY edition), since that lets you continue playing after the end and adds to the main story. As an alternative you could use a mod, but I wouldn't advice using too many of them in your first playthrough.
