Google Image Search has, for me, the most useful results of all the image search engines.
Some time ago it made it's functionality slightly worse with a combo box to select which size of image you wanted. This required two clicks (one to open the box, one to select) to select your size as opposed to the previous one click to select a link which was always displayed.
Recently, the functionality of the page was essentially removed altogether when all metadata was hidden from view. Now, instead of using your eyes to scan the page looking for the picture of the size you want, you have to use your mouse. The information regarding the picture dimensions are only displayed when the mouse is hovered over the picture.
The reasons for this change are fairly clear. Along with the mouse-over behaviour, the image results are formatted more cleverly allowing for more result per page on, for example, widescreen or large browser windows. Also, the results page looks very clean. This is because there is no information on it.
Google offers no preferences to adjust this behaviour.
However, this change can be undone by disabling Javascript for the images.google.com domain. A side benefit of this is that it also removes the combo box size selector and replaces them with much handier links. The disadvantage is a fixed number of results per line and page.
For me, I prefer to use my eyes to scan a page, not a mouse.
With Javascript:
Without Javascript:
