Should I purchase the FO 1-2 now? or at least 2?
You definitely should. I'm replaying them as we speak. At least until I can afford to do some major upgrades to my PC for FO3. *** tuition is killing me.
What Mario was to the 2-d platformer, Fallout was to isometric turn-based RPG. If they had been console games instead of PC (I realize they wouldn't have been as good without the mouse control scheme, but I'm referring to the market share), they would have been on par with Final Fantasy.
Sadly, they died out with the rest of the isometric turn-based games as everything had to be real-time, adrenaline-charged, and multiplayer to be successful. Who knows, if FO BOS had been a real-time RPG and retained that distinctive Fallout "attitude", maybe FO would be on its 5th or 6th game as a successful RT RPG franchise like all the D20 games (Baldur's Gate, Neverwinter Knights, and KOTOR for those who don't know what D20 is).
What I think that Bethesda has really hit on in FO 3 is that FO is all about the quirky 50s quasi-humorous overall feel of the game. You can turn FO into almost any RPG genre you want it to be as long as you keep going back to that overall aesthetic.