If 5 images were taken in succession, and are extremely similar - it is a pain to choose. If you could select say the eye and tell lightroom to find the image which has the sharpest eye - that would be cool.
This could be paired with duplicate image functionality, or face detection somehow
I've been asking for this for a while. Programmatically, they'd only have to ask for the user to select a range of images, select an area that the user cares about sharpness (eyes) and then LR would set targets on the remaining images looking for eyes within the nearby region maybe using a simple least-means-square method. Then, a simple FFT is applied to a bound box around the target and the images ranked by frequency (higher frequency = sharper, higher-contrast edges = PICK).
I like this idea and would use it frequently. If Adobe deems it too far down on the priority list to implement. how about a trivial addition.
Add File Size as a Library View Option.
In my experience, files that are out of focus, or slightly blurred are smaller that crisper ones of the same scene. I suspect this is a byproduct of compression - sharp photos have more detail to preserve. If I had the choice of displaying File Size in the "Info x" templates, I would be able to quickly glance at the sizes and pick the best 2 out of 5 to visually inspect.
Being able to select an area to compare sharpness for a particular area would clearly be superior, but I suspect 'file size' would be good enough for most cases.