*goes into comics geek mode*
Okay, for the record, the big headed guy on the cover is Uatu the Watcher, a member of an advanced alien race whose purpose is to observe developing civilizations and report his findings to his superiors. They have a strict policy of non-intervention. He intervenes because he decides he is rather fond of humanity and doesn't want to see Earth eaten (he'd have nothing to watch, see).

Galactus is the big, purple suited guy with a big head and even bigger hat what actually eats planets.

Just in case anybody gets confused.

Spoiler: Earth doesn't get eaten. 8-)

Oops, fixed :)
You can see I never collected Fantastic Four, I'm glad these highlights are automated not based on my knowledge :)

Could you refine the search with the phrase "amazing spider-man #1" (adding in the number symbol)? As you stated, you're working with very large numbers, but X-Men 3 is arguably a more popular movie than the X-Men #3 comic, so I could see a lot of skewing with that particular issue, which I don't think actually holds that much love from the fans.

In comics you're more likely to refer to #3, whereas with movies, you're more likely to just say "3."

Ragdoll, the "#" sign in phrases is ignored by Google. Take a look at the following search:

http://www.google.com/search?hl=en&q=%22amazing+spider-man+%23300%22

The top result in bold reads "Amazing Spider-Man #300".
The second result in bold reads "amazing spider-man 300".
So either way will return both.

What I do though is ignore the first 10 and last 10 issues of each series. The #1 of every comic is always a highlight anyway in comic books and has many mentions, and it also doesn't have 10 neighbors to each side, so I decided to ignore it...

As a FF4 fan (and owner of some old issues), ditto what J.McNair said. Galactus is a HUGE dude.

Nifty project Philipp ... wonder if you somehow compared your Google "popularity" numbers to the market prices of the comic books ... bet there would be some good correlation.