Why are most comments referring to having used this in the past tense? I was under the impression that it was still the best image viewer in town, on Windows at least
The built-in viewer in windows is fine. I can't really think of a feature that it doesn't have that I need. Could you say why irfanview gets your vote?
The batch image manipulation features it offers are pretty handy. Plus you can press L or R to rotate an image and it has lossless rotate options as well.