In 1903, the Boston Americans (later, Red Sox) defeated the Pittsburgh Pirates five games to three in the first ever World Series. This past October, The Boston Red Sox defeated the St. Louis Cardinals four games to two, in the most recent World Series. Not counting the two years when there wasn't a series- 1904 and 1994- that makes 109 total. Those two non-series years happened for two different reasons; in 1903, Giants manager John McGraw refused to play out of spite for his hatred of American League President Ban Johnson, while ninety years later, the season ended with a players strike in August of '94, much to the lament of Montreal Expos fans. ( an MLB best 70-44 at the time of the strike)
Out of the 109 series played, over half of them (55 total) are by four teams: The Yankees (27), Cardinals (11), A's (9) and Red Sox (8). Then if you take the next four teams- The Giants (7), Dodgers (6), Pirates and Reds (5 each) -the total is 78 titles from 8 teams. That leaves 23 franchises winning the remainder of the 31 championships, some of them multiple winners (Tigers, Braves, White Sox, Orioles, Twins/Senators etc.), and some just only one so far, (Royals, Angels and D'Backs).
Granted, 14 of the remaining teams are expansion teams, and they account for nine of them, but It just goes to show you how little parity there is/was in general. Not to say that there haven't been moments of true parity; the '78- '87 seasons are the ultimate example, with a different team winning it all in a ten year span. The early '00s looked to be similar, with the Yankees finally losing some steam after dominating in the late '90s, early '00s. Two teams broke 80-plus year curses that decade, (Red and White Sox...back to back years in '04 and '05), the Angels won their first in '02, breaking a 42 year drought. Newer teams got in on the act too- Marlins with their 2nd ring in six years, D'Backs winning it all in their fourth year- but of course the decade ended on yet another Yankee title.
One of the weird things about the Yankees dominance overall, is that it took them 20 years to get their first ring ...in 1923. Then there were years in the ensuing decades where they'd win two, three, four and even five in a row (49-53...Stengel's best team). Sure, there have been droughts; no championship between 63-76, and another dry spell during the '80s and early '90s. The latter one is the most significant, because the '80s are the only decade since their first title in '23 that the Bronx bombers didn't win a World series, despite the presence of Hall of famers Ricky Henderson and Dave Winfield...oh, and Donnie Baseball. Those teams scored a ton of runs and are a testament to the old adage: "pitching wins World series'."
Even if the Yankees don't win one for the next 25 years, they would still be the dominant all time champ...The Cardinals-the closest to them- would have to win 16 to tie, and I'm kind of sick of them anyway. I wouldn't mind some of the teams who won pennants in the past, but not the World series, get in on the act, like the Padres, Astros, Rockies, etc. Just not the Rays...they're the Bosox biggest competition now (ha). I think the Nationals (formerly Expos) and Mariners should have to win a pennant before they can win it all...sort of like an initiation into the club.
Of course, there are the long suffering teams: Pirates, Orioles, Tigers, Mets and Royals, whose fans surely would appreciate a title after 25-30 years of coming up short. There are the Indians, who despite having one of the most dominate teams of the '90s, never won it all in that decade...and then, the are the Cubs. For years, I sympathized with the boys from Wrigley; they seemed like a cousin to my equally hapless Red Sox. However, the difference was, at least the Sox actually would go to the World Series here and there, while the Cubs haven't won a pennant since 1945, which is actually a longer drought than the Indians last Championship in '48.
When the boys of Fenway won it all in '04...and again in '07, and again this past year, I felt my alliance with the Cubs slipping away. It's not that I don't still sympathise, it's just that I don't really relate to their plight anymore.. My N.L. team for years has been the New York Mets, mostly because I've lived in Brooklyn for a while and Mets fans hate the Yankees as much as Sox fans do, if not more. People say, "What about '86, Bill Buckner, etc.", and I say, after '04, all that is washed away. The Cubs still have the billy goat...they still have the black cat in '69...they still have the Bartman incident...and until they win it all- or at Least win the pennant- that stuff will still be relevant in some weird way. Trust me, I know...notice how nobody chants "Nineteen-eighteen" at Yankee Stadium anymore?