In anticipation for the new Fallout game Fallout: New Vegas, STEAM is offering their Bethseda titles at a very generous discount.
The Elder Scrolls IV: Oblivion Deluxe GOTY Edition - $8.50 (-66%)
The Elder Scrolls III: Morrowind GOTY Edition - $5.00 (-75%)
Fallout 3 GOTY Edition - $24.99 (-50%)
store.steampowered.com/sale/bethesda_weekend
Personally would get Fallout 3 and Oblivion for the modding community alone since the vanilla versions just blow hard and the community basically saved those games from being one and done type of games. Of course I don't need to explain how awesome Morrowind was and still is.