Which is the best Hellboy storyline?

One of the most popular Hellboy stories is one called Conqueror Worm in which Hellboy and a homunculus notice a space capsule entering the atmosphere near a castle in Austria. After investigating it, they realize that it was launched by a Nazi scientist in 1939 in order to encourage evil alien beings to come to Earth and wreak havoc on the enemies of the Third Reich.

When they open the capsule, a poisonous gas emerges that turns humans into non-sapient frog monsters. Out of the capsule also comes an ancient creature called the Conqueror Worm. The homunculus, Roger, engages in a battle with the worm and eventually defeats it.

It turns out that the Nazi scientist who originally sent the capsule is still alive and has replaced most of his organs with robotic body parts. He also reveals that he has despaired of conquering the world and only wants to see it end. He is also defeated, and his disembodied head is thrown off a cliff leading to his demise.