Well obviously you don't like those albums too much, and you obviously prefer the 80's Bon Jovi, but for many I think that Keep The Faith and These Days are two of the bands biggest albums.

Personally I see it all as 4 eras, the first being when the band where quite small (Bon Jovi and 7800 Fahrenheit), then came the successes of Slippery When Wet and New Jersey when the band where propelled to stardom. Then I see the re-invention as it where with Keep The Faith and These Days. Finally after a few years apart comes another re-invention with Crush and Bounce. Perhaps the new album will herald a new era in the bands history.

Personally I cannot pick a single time that sums up what I like best about the band, I do like most of the albums, less so the first 2, but I enjoy different eras of the bands progression for what they are. I don't expect, nor would I particularily enjoy hearing lots of the same, which is why I like Bon Jovi. There are other bands that I listen to and their material can sound quite similar from one album to the next, not identical but enough to see a style, but with Bon Jovi comparing any two albums you can see quite a dramatic change in style I think.