What do you want exactly?
A swiss army knife of image viewers with some basic image editing capabilities. Irfanview will open just about damn near any image format (and a bunch of multimedia formats I don't really bother with) and also has the ability to do basic things like rotate an image or reverse it. It has plugins that allow you to select a part of the image and apply a blur on it so you can edit personal details out of a screenshot. That's the kind of thing that I'm looking for.
EOM does a good job of just displaying images, but is weak on the editing or simple image plugins. The mentioned xnview is closer but was clunky when I tried to use it several years ago. The GIMP is pure overkill. Shotwell is really for displaying camera outputs and collections. Inkscape is for drawing not dealing with an image you already have.