The thing that strikes me the most about Ebert is that he gave every movie a fair chance. He never seemed to go into a movie expecting to hate it; whenever he brought out the poison pen, there was a sense of disappointment. He loved all kinds of movies and while he had his biases, he was always willing to overcome them. His distaste for 3-D didn't prevent him from noting when the technique was used well in Avatar, Hugo, or Cave of Forgotten Dreams; he would decry a film like I Spit on Your Grave for reprehensible exploitation, but find artistic value in the similarly unpleasant Last House on the Left.
One of the most important points he made was that a movie is not good because of what it is about but how it is about it. Through his decades-long career Ebert reviewed just about anything the Chicago Sun Times had a mind to send him to; we never saw Pauline Kael or John Simon weigh in on Infra Man or Godzilla 1985, but somebody had to. There were many, many times I disagreed with his opinions, and people would bring up questionable deviance from the consensus as though star ratings were the true measure of a critic's worth, but he engaged with film as both trash and art, and everything in between.
Roger Ebert's life was cut short, but he got a lot out of it and never lost his enthusiasm for life even as he pondered the end of it. His optimism was inspiring, and may have been part of why he went into every film with the hope that it would amaze him. That's an attitude worth holding onto.