NFL = Super Bowl (1967-onward)
MLB = World Series (1903-onward)
NBA = NBA/BAA Championship (1946-onward)
NHL = Stanley Cup (1893-onward)
TOTAL POSSIBLE: 335
I am only counting championships that were won in THAT metro area, not the franchise as a whole.
Anyways, here we go:
1) New York CSA
NFL: Giants (3), Jets (1) = 4
MLB: Yankees (27), Giants (5), Dodgers (1), Mets (2) = 35
NBA: Knicks (2) = 2
NHL: Rangers (4), Devils (3), Islanders (4) = 11
TOTAL: 52 championships
2) Los Angeles CSA
NFL: Raiders (1), Rams (0) = 1
MLB: Dodgers (5), Angels (1) = 6
NBA: Lakers (11), Clippers (0) = 11
NHL: Kings (0), Ducks (1) = 1
TOTAL: 19 championships
3) Chicago CSA
NFL: Bears (1) = 1
MLB: Cubs (2), White Sox (3) = 5
NBA: Bulls (6) = 6
NHL: Blackhawks (4) = 4
TOTAL: 16 championships
4) Washington DC-Baltimore CSA
NFL: Redskins (3), Ravens (1), Colts (1) = 5
MLB: Senators (1), Nationals (0), Orioles (3) = 4
NBA: Capitols (0), Bullets/Wizards (1) = 1
NHL: Capitals (0)
TOTAL: 10 championships
5) Boston CSA
NFL: Patriots (3) = 3
MLB: Braves (1), Red Sox (7) = 8
NBA: Celtics (17) = 17
NHL: Bruins (6) = 6
TOTAL: 34 championships
6) San Francisco Bay Area
NFL: 49ers (5), Raiders (2) = 7
MLB: Giants (1), Athletics (4) = 5
NBA: Warriors (1) = 1
NHL: Sharks (0) = 0
TOTAL: 13 championships
7) Dallas-Fort Worth Metroplex
NFL: Cowboys (5) = 5
MLB: Rangers (0) = 0
NBA: Mavericks (1) = 1
NHL: Stars (1) = 1
TOTAL: 7 championships
8) Philadelphia Area
NFL: Eagles (0) = 0
MLB: Philies (2), Athletics (5) = 7
NBA: Warriors (1), 76ers (2) = 3
NHL: Flyers (2) = 2
TOTAL: 12 championships
9) Houston Area
NFL: Oilers (0), Texans (0) = 0
MLB: Astros (0) = 0
NBA: Rockets (2) = 2
NHL: NO TEAMS
TOTAL: 2 championships
10) Atlanta Area
NFL: Falcons (0) =0
MLB: Braves (1) = 1
NBA: Hawks (0) = 0
NHL: NO TEAMS
TOTAL: 1 championship
If you want to add your area, by all means do so!