What is your favorite 3-stage line? An evo line that you love throughout all 3 stages.

EASY MODE: All 3-stage lines count.
NORMAL MODE: Evo lines that are only 3-stage due to crossgen (pr)evos don't count.
HARD MODE: No starters.
NIGHTMARE MODE: No pseudos.
IMPOSSIBLE MODE: No trade or stone evos.

For me it's the Metagross and Magnemite families.