Fallout for it's lore, Metro for it's visuals.
Honestly Fallout had more going for it story wise, compared to Metro, where you had up to 3 different types of foes to go against, and a story that was rather self contained. I liked Metro/LL's stories, but compared to Fallout, they are quite small in lore/tales to tell.
Step right up come on in, feel the buzz in your veins, I'm like an chemical electrical right into your brain and I'm the one who killed the Radio, soon you'll all see
So pay up motherfuckers you belong to "V"