Just found this thread and loving it. I bought a Rega RP1 with an arm upgrade a bit over a year ago and have been loving it.I've found so far that my worst vinyl sounds like my better or best CDs so I'm pretty pleased.
I too picked up the Led Zep reissues. I had only heard a handful of Zep prior, and only via columbia house record club cassettes ha ha. The first drum kick in "Your Time Is Gonna Come" nearly knocked me out of my chair. So yeah, they're quite the revelation to my ears.
Another one that struck me was the first album by The Stooges. I've owned it on cassette and two separate CD versions, and none of them sounded any good compared to the 180g vinyl Rhino put out. Also, if you're a Bob Dylan fan, the Mono boxset of his first 7 or so albums is a must. The stereo versions of the early solo folk albums always annoyed me since it put the vocals in one speaker and his guitar in the other. Now they blend properly and sound like you're in the room. The electric albums benefit too, Highway 61 Revisited never sounded better. The whooshing organ at the start of "Like a Rolling Stone", I'm gonna go listen to it tonight ha ha.