A fine writer, mind, and above all film lover - would that more of us could meet or even approach his standards in these fields.
I won't write a long eulogy for him here - there are plenty of people, most of them much more able than I, who have written or are at this moment writing ones of their own. Besides, if you're reading this you undoubtedly know about and admire the man just as much as I do.
Instead, go to his website (rogerebert.suntimes.com), look through his list of Great Movies, and read his words on a few titles. Be sad there won't be any more appearing there, but above all be glad there are as many as there are now.