In in sales it would be the simulation SIM prefix created by Will Wright or Mario.

In terms of great games, I would have to go with Civilization.

0.0.0.1?
1.3.3.7?
God I wish that last one was my IP... that would be awesome. And I'm glad I was not alone in reacting that way.

Kind of a weird question though, and I don't really know what to answer.

In sales Mario is firmly on top with poke'mon second, I know that for sure, not sure about SIM ____, I beleive it's lower (around 5th or 6th).

The Legend of Zelda for me too.

Well in terms of main series, it goes Mario, Pokemon followed by The Sims.  Looking at the rough estimates here http://en.wikipedia.org/wiki/List_of_best-selling_video_game_franchises it looks like I underestimated the sales of Pokemon and guessed to high for Sim City, Sim Life, Sim Earth, Sim Ant, etc.  I would guess that Sim franchise would be very close to the Pokemon games, but I don't think anyone has all the data to actually answer that question.

7 for Zelda

You could always get a router and give yourself that IP ;)

i can't comment on best IP but most popular is probably pac-man or mario.

....excuse my stupidity but what the hell does IP stand for, I've been trying to figure that out for months

IP in the case of this thread is supposed to stand for Intellectual Property