Among all of his great roles, I always come back to Frank in Wrestling Ernest Hemingway. The character was so much smaller and insignificant than Harris ever seemed in interviews. He was a presence on Letterman, Leno or even TVO (for those of you who are from Ontario).
I wouldn't call him a force of nature -- not only is it a cliche but it might be overestimating nature. But he was an actor of the first order. He could act his way out of his own presence in a way that Laurence Olivier, Tom Cruise, or even Peter O'Toole never could.
Don't get me wrong, he brought a characteristic verve to every role that I've seen him in. But he's always stopped being Richard Harris, Rebel Angel come Raconteur, on screen and started from the first frame being someone new.
I don't miss people I don't know. But I do wish he had time to make a few more movies.
Regards.
PS If you liked Harris, you really should check out the movie The Field, and try to forget about the song MacArthur Park.