I get it. You've said that 1500 times. Now what makes Fallout 3 & New Vegas different from Lego Starwars.
The gameplay has been revamped. New Vegas includes iron sights, factions, enhanced stealth combat, ammo types, companion wheel,
a wider range of voice acting (you will never hear the same voice twice in a row), over 200 new weapons/items, the ability to craft armor or goods, hardcore mode,
a huge new environment that could take over 200+ hours to explore, etc.
Fallout 3 story: Fallout 3 starts in Vault 101, which you are taken to as a child by your father, after your mother is killed at your birth. When you reach 18 years of age, your father escapes the vault and you need to follow in his footsteps to try and find him.
Fallout New Vegas story: In Fallout: NV, you play as a courier who was intercepted and shot in the head by thugs. After a doctor patches you up, you journey around the Mojave wasteland to find the person who shot you. Once you meet him, the story spirals off into 4 alternative endings.
As for the lego games you have about less than 10 hours of gameplay, about a 5 minute story that is loosely based off the movie, slightly more characters that look the same as the last ones and have same animations.
Am I leaving anything out?