Why is Fallout so great? The mood. The humor. The rocket launchers...
Also, your vault dweller won't ever be black or white and often will have to make decisions that won't please everybody. No good solution ever!
As for the voice acting, it's... unforgettable! Killian holds a special place in my heart. Also, you ought to read the manual. It got interesting recipes and info on nuclear blasts.
Oh, finally, the game is just a perfect mix of cynism, tragedy and violence. You've got to love the gore there... and heavy weapons are really fun to use. You'll also chuckle and smile a couple of times. And you'll feel that little something in really tense moments once in a while. "Noooooo, whyyyyyyyyy!!!". Feels a little short once you've done it, but I suppose there is always the replay value. I heard you can beat the game without killing any character. So, yes, this is a game definitely to try. If hard to find, it's relatively cheap. Bad graphics, bad controls, but wonderful story and music! Be ready... and watch out for the radiation!