Ivy Bridge: 21 pages http://www.anandtech.com/show/5771/the-intel-ivy-bridge-core...
I'm sure there are others.
The SSD series were not technically review but went well beyond 20 e.g. http://www.anandtech.com/show/2829/ is 27 pages.
edit: http://archive.arstechnica.com/cpu/03q1/ppc970/ppc970-0.html with the glorious old design