hmmm. I think one difference here is how people look at 'the best' album and that may have a lot to do with the differing choices.
You say 7800 is their best (or you like it best) because it is rough, hard and generally more what Jovi is supposed to be/used to be. I don't disagree, but there is no way in hell that I'd ever put an 80s album on my favorite list just as I will never put an 80s band on my list of favorites. I have nothing against the 80s -- enjoyed them to bits.
When I say my favorite album, I don't look at it from the perspective of what it was supposed to be, but rather how I can relate. I don't relate to the 80s much anymore - it's mostly nostalgia. Maybe I am stuck in the 90s then, lol.
Most people that voted TD as their favorite album did so due to the lyrics. Not that the music isn't awesome, but I think the lyrics are what most people can relate to when they say they love TD. So really, in a perfect world, BJ would come out with a 7800 sound - rough, hard and all, but no cheesy lyrics about parties and chicks
my 2c.