Out of curiosity I did a search on LiveJournal.com of all of the people who list Family Guy and Invader Zim as interests...
Family Guy produced a healthy 768 matches. Blow jobs produced only 114 matches, so apparently Family Guy is more popular than blow jobs.
Invader Zim produced an overwhelmingly healthy 3254 matches(only 315 less than Metallica and 1114 more than Britney Spears).