Been reading these posts and had to submit my humble reply.
I go through these phases where I'm obsessed with Bonham for two weeks, then Buddy for two weeks, then Tito Puente for two weeks and so on. Well, for the past week it's been Neil and Rush. It seems every couple of weeks my opinion of "who the greatest drummer is" changes so I change my focus of who to study and learn from.
I've come to realize the greatest drummer ever is the one I'm currently hooked on and learning from. The drummer who is inspiring me to learn new fills, trying new time signatures, practicing with an effing metronome etc. Their greatest isn't measured in their feel and technique alone - Their greatness is measured by the affect they have on drumming, the music community and the timelessness of their art and passion.
To me, "great" means not easily forgotten or irrelevant. It doesn't mean how many 64th notes someone can play in a fill, their double bass speed, the number of tattoos or anything else. To me greatness means to inspire and there are a helluva lot of good drummers who are inspirational to me.
I work from home so today I was watching Rush In Rio and got inspired to go play for a bit - Grabbed my sticks, ran upstairs to my office and completely lost a half hour to playing. I don't remember what I played, I don't remember what happened around me and I don't care. I know for that 30 minutes I was the greatest drummer in the world because I was playing well, playing creatively, learning a few new tricks and having fun.
This week Neil is the greatest drummer ever because he inspired me to get away from SAP for a spell and work on my chops.
Thanks Pratt