In what? Basketball? Baseball? Soccer? Bowling? Dog shows? You need to be more specific in your question.
The UCLA Lady Bruins have won the most National Championships in Collegiate Fastpitch Softball...I believe they have won 25 or 26 National Championships.
The Yankees
in what sport
texas
Total, they have won 21 National Championships and rank anywhere from #7 to #11 in the nation for the most Championships obtained.
UCLA Bruins
Florida
They have won 21 national wrestling championships
No Alabama football coaches have won national championships.
North Carolina, they have won 27.
The Green Bay Packers have won the most league championships, with 12 wins, including three Superbowl wins.
The Alabama Crimson Tide with 14