Prefer in what way?
For vacation, easily Miami. Better beaches and nightlife, plus the clubs don't close till 5:00. And South Beach has everything you need in walking distance, so no car needed.
To live... that's more complicated. They both have a ton of attractions, natural beauty, perfect weather, cultural diversity, and S HITTY traffic
. L.A probably comes out ahead in most of those categories, but in Miami you can get super cheap flights to the Caribbean! Oh yeah, L.A also wins for LGBT scene.
