Selecting multiple blocks of text. Scrolling with the mouse wheel. / for quick find (and ' for links).
edit: I wonder if this is similar to the difference between Windows and Mac. Windows might be inconsistent in the small things (e.g. button padding), but it gets the large things right. Mac gets the small things right but the large things horribly, horribly wrong. Chrome seems to get the small things right too (e.g. tab animations), but overall Firefox does much better.
