Destructoid - The Fallout series has become popular with the current generation of gamers thanks to Bethesda's Fallout 3 and Obsidian's Fallout: New Vegas. If Fallout 3 was your first trip into the post-apocalyptic wasteland, you might want to take a look at where the series started. Of course, you'll want to mod it a bit first to make it looks less like a pixilated drug trip.
Fallout has a very simple main quest, but there are tons of side quests. If your are familiar with the newer Fallout games, you'll be able to pick up the gameplay of Fallout pretty quickly. The biggest difference is the isometric view and the turned-based combat. It's like playing all the combat using VATS in Fallout 3. The story, weapons, skills, and open world are almost identical to the newer games.