Mainly selections, adjusting the background independently of my subject. While the Lightroom tools can do this (kinda) results from PS are seamless when compared. Curves also has more control and somehow looks better. I also use the patch tool quite a bit, the clone tools within Lightroom are quite restrictive.

If Lightroom had better selection tools, patch and better curves I would be down to about 1% Photoshop.

Of course if I am doing a large print, or some published work like the cookbook I have been doing recently then I would spend more time on each image and Photoshop is much better for the detailed work like that.

Cheers

Cris.