What camera is easiest to use with glasses?
Ok, live view and ground glass are obvious winners. I have yet to find an optical viewfinder that doesn't require peering around the edges to check composition, with the exception of a rangefinder and 50mm or longer lenses.
What is your experience?
I have worn glasses all my life. What's easiest to use, however, is a bit too personal and qualitative to declare for all users ... But here's my experience:
Because of the viewfinder, my favorite 35mm SLR of all was the Nikon F3/T with High Eyepoint finder. The viewfinder optics were superb and it allowed me to see everything at a glance, clearly and crisply.
Having worked with a number of different Canon, Pentax, Nikon, Panasonic and Olympus DSLRs, from "full frame" to FourThirds, in the past decade, the one that brings what I loved in the Nikon F3hp back to me is the Olympus E-5. It has just about the same relationship of superb optics, magnification, and information displays, and screen quality. It is very easy for me to see critical sharpness with it when focusing manually.
Leica M optical viewfinders also work well for me in general, although I prefer the older four frameline version of the viewfinder (35, 50, 90, 135 mm) over the later six frameline versions (28, 35, 50, 75, 90, 135). The latter seem cluttered and there's not enough eye relief for me to see the 28mm frame lines with glasses on.
The current generation of EVFs now used in the Panasonic Lumix G models with built in finder, the Olympus VF-2 for the Pen line, and the Ricoh VF-2 for the GXR also work well for my eyes: I can see the image in the viewfinder clearly and see the critical focus point snap in and out accurately. The newer, higher resolution ones in the Sony NEX 7*and (optional) for the NEX 5n sound great.
I had good experiences with Hasselblad, Mamiya and Pentax medium format SLR viewfinders too.