Fallout 3 is one of those dangerous games that, once it gets its hooks into you, you won't be able to stop playing.
The quests in Fallout 3 are excellent. Each one has its own branching storylines, with options for you to be good or evil as you see fit. For example, one quest has you helping a kid rid a town of giant fire ants. You have to go down into a metro station to find the source of the trouble, and lo and behold, you find a scientist who claims his experiments went wrong. After you rid the town of the fire ants, you can either find the young boy a home, or leave him to fend for himself in the harsh world. Little choices like these will affect your karma meter, which judges how good or evil your player is. The main quest in Fallout 3 is also incredible; it has you following the footsteps of your dad. However, to me, the best part about Fallout 3 wasn't the quests; it was the exploration and freedom.
The graphics in Fallout 3 are amazing, especially on an HDTV with HDMI cable. The views in the Capital Wasteland will astound you, with ruined buildings, swirling dust, blackened, leafless trees, satellites and radio towers looming in the distance, and that ever present, "now where do I want to explore next?" The sound in Fallout 3 is also great. The guns sound powerful, the clink of armor and gear as you run sounds cool, and just every little detail go towards making this one of my favourite games of all time.
Fallout 3 is amazing. The graphics, the Capital Wasteland, all the armor and weapons and items, the interactions with people, who are clearly having a hard life. There is just so much to do in the Capital wasteland, so what are you doing! Get out there and save the people of the wastes... or cause their destruction. It's your choice. That, I think, is the beauty of it.