It's not that hard to make a list of guitarists in rock music who were not only great guitarists but important in the history of rock guitar. The first few names are gimmes: Jimi Hendrix, Jeff Beck, Jimmy Page, Eric Clapton, Eddie Van Halen. After that, people can get quibbly about who really deserves to be on the list, but there are certainly a bunch of names that are likely to appear on most people's versions of the list.
I was thinking about who would be on the equivalent list for drummers, and not that many names jumped out at me. Without testing the borders of "rock" by going out into the rhythm-and-blues family (where we'd immediately get Gene Krupa and Buddy Rich, amongst others), only two names occurred to me that should be on everyone's list: Keith Moon and Neil Peart. But I feel like there are others that just aren't coming to mind.
It's a truism that drummers don't get the glory that guitarists get, generally. (Neil Peart had to be superhuman to break that glass ceiling; I recently read someone's comment on a forum that the one thing that most made him doubt his atheism is watching Neil Peart play.) But even so there should be more names that jump to mind. I can think of drummers who did good work, but the standard is not only that they were great but also that they were important to the history of rock drumming, perhaps because of innovating techniques or defining styles (the way Gene Krupa did), or for combining elements from different genres, or something.
So, who am I forgetting?