well, they all "count" in that you never know which a particular lender is going to look at.

it actually breaks down to 5 credit scores (this of course is "pre" vantagescore)

you can get a FICO based score from all three, when you pull your report from MyFICO.com they will ask you which of the three you want them to use to calculate the score.

then, as Poundwise correctly points out, Experian and Transunion have their own score they generate off their own reports. Experian's scale goes to 830 and I believe Transunion's goes to about 950 making it difficult to do an apples to apples comparison, that is, an 830 while grand on the FICO model isn't quite so hot when using Transunion's system.

Equifax has apparently not seen it as cost effective to create their own scoring model so again, as Poundwise says, they just use FICO.

I for one no longer bother with the Experian and Transunion scores, I just go to MyFico and pull each on a rotating basis about every 4 months and my free report in the space in between, keeps my eyes on my report every other month. Probably not the wisest use of my money but I am a paranoid character and it only totals to $30 a year.

And for what it's worth, the vantagescore, when it gets rolling is only going to reduce the total to 4 (three versions from FICO and the vantagescore combo from the three sisters). I have heard as well that even the vantagescore might vary depending on which of the three you get THAT from due to the fact that they don't talk to each other much. But I'm not sure about that last part.