Well, here's a real neat article written by who else but Rahul Dravid who has probably played the most games alongside Kumble both in first-class and international games combined. And I suppose this little paragraph embedded in an article that clearly reflects the admiration that Dravid has for the man, says it all:
His attitude makes him a dream to captain. When I led against New Zealand in 2003 at Mohali and we lost the toss and had to bowl first on a flat wicket, not once did Anil complain. Occasionally a bowler, faced with an unresponsive wicket, might give up mentally, but not Anil; never did he say, "Rahul, give me a break." He just bowled on and on. He does not know what giving up means.You can say that again, Dravid.