The thing about Whitesnake is that they're not Queen, they're more like AC/DC. If you like Cryin' In The Rain, or "Still Of The Night", you're probably going to like the rest of the album. The pre-American "Slide It In" (there is a UK version and a US version; the US version is the more "popular" one) era is all more bluesier, more Deep Purple-ish (and even had Jon Lord and Ian Paice for a while), while the post-American "Slide It In" era (to the present) is more what you think of when you think "Whitesnake", that is, Tawny Kitaen on the hood of a Mercedes.
I happen to like both eras, because I like Coverdale's voice, but I find myself going back to the earlier stuff more frequently. By the way, if anyone likes Whitesnake, find the "Starkers In Tokyo" CD; it's Adrian Vandenberg on acoustic guitar and David singing and his voice is just velvet, gold, silk, and macaroni and cheese all wrapped up in one. That version of "Don't Fade Away" is one of my top five Whitesnake songs.