I am personally partial to either Sushi Jo (West Palm Beach/Palm Beach Gardens) and Sushi Saigon (South Beach) but there are TONS.
Maybe this discussion is better split into two:
Favorite Value Sushi (Fresh and High Quality, but for a good Value), and Most Innovative Sushi (Price being no object).
Value: Sushi Saigon (SoBe) - Very Fresh Fish, great selection, nice ambience
Innovative: Sushi Jo (PB) - Awesome specialities, great non-rolled items, fresh fish, wagyu beef, amazing unique items