Unfortunately I live in an area where we have no access to any camera shops except for one that specializes in Nikon and they are super high pressure sells, not to mention their prices are 20% more then internet pricing. When your talking $600+ USD that is a huge difference. So unfortunately I was not able to look through my camera before I bought it. I had do lots of research online and hope for the best. Unfortunately I am not happy with the viewfinder. It is very, very small. Meaning the field of view. Which makes it hard to see if an image is sharp or not. Is the 20 or 30D any better? I am thinking of returning it. Another theory is that maybe I just need to get used to looking through a DSLR viewfinder vs binoculars. Any info welcome.
Nikon D80 and Pentax K10d are known for good, pentaprism (not pentamirror in cheaper DSLRs) finders. I haven't compared the Canon x0d in a while so no comment. dpreview.com may have some info on their finders.
The 20D/30D viewfinder is considerably better than the 400D finder - which is just as well, as the 400D VF is not a good one: very small and hard to see what you are doing.
People say that some of the Nikon and Pentax finders are better again - I can't comment on that, have not tried them. But it might be useful to remember that all digital SLRs excepting only an ancient Kodak model, all of the the Canon 1 Series units, and the Canon 5D are poor when compared with a 35mm film SLR. Size matters.