I looked at the NCAA tournament and results from the tournament since the field expanded to 64 in 1985 and from what I see below the ACC is going to be best conference for the foreseeable future.
From 1985 until 2013 17 teams and 8 conferences have won a national title
1st ACC-8 (Duke 1991, 1992, North Carolina 1993, Duke 2001, Maryland 2002, North Carolina 2005, 2009, Duke 2010)
t.2nd SEC-6 (Arkansas 1994, Kentucky 1996, 1998, Florida 2006, 2007, Kentucky 2012)
t.2nd Big East-6 (Villanova 1985, UConn 1999, Syracuse 2003, UConn 2004, 2011 Louisville 2013)
4th B1G-3 (Indiana 1987, Michigan 1989, Michigan State 2000)
t.5th Big XII-2 (Kansas 1988, 2008)
t.5th Pac-12-2 (UCLA 1995, Arizona 1997)
t. 7th Metro-1 (Louisville 1986)
t. 7th Big West-1(UNLV 1990)
Championship game appearances by each conference in the last 29 years( Big 8 counts as Big 12 and I am counting Memphis and Michigan)
1st- 13 ACC- (86,90,91,92,93, 94, 99, 01, 02, 04, 05, 09, 10) 4 teams Duke, Georgia Tech, Maryland, North Carolina
2nd Big East-10 (85x2, 87, 89,96, 99, 03, 04, 11,13) 6 teams Georgetown, Villanova, UConn, Seton Hall Syracuse, Louisville
t.3rd SEC-9 (94, 95, 96, 97, 98, 00, 06, 07, 12) 3 teams Arkansas, Florida, Kentucky
t.3rd- B1G-9 ( 87, 89, 93, 00, 02, 05, 07, 09,13) 5 teams Illinois, Indiana Michigan, Michigan State, Ohio State
5th Big 12- 6 (88x2, 03, 08, 12) 2 teams Kansas, Oklahoma
6th Pac-12 4 (95, 97, 02, 06) 2 teams Arizona, UCLA
7th Horizon-2 (10, 11) 1 team Butler
t.8th MWC-1 (98) Utah
t.8th CUSA-1 (08) Memphis
t.8th Metro-1 (86) Louisville
t.8th Big West (90) UNLV
Conference records in the championship game
ACC 8-5 (5-0 vs. B1G, 0-1 vs. SEC, 0-2 vs. BE, 1-0 vs. Pac-12, 1-0 vs. Horizon, 1-0 vs Big XII, 0-1 vs, Metro, 0-1 vs. Big West)
SEC 6-3 (1-1vs. B1G, 1-0 vs. ACC, 1-0 vs. BE, 1-2 vs Pac-12, 1-0 vs. Big 12, 1-0 vs. MWC)
B1G 3-5 ( 0-4 vs. ACC, 1-1 vs. SEC, 2-0 vs Big East)
Big East 5-3 ( 1-1 vs. Big East, 2-0 vs. ACC, 1-0 vs. Big XII, 1-0 vs. Horizon, 0-1 vs. SEC, 0-2 vs. B1G)
Pac 12 2-2 (2-1 vs. SEC, 0-1 vs. ACC)
Big 12 1-3 ( 1-1 vs Big 12, 1-0 vs. CUSA, 0-1 vs. BE, 0-1 vs. SEC)
Horizon 0-2 ( 0-1 vs. ACC, 0-1 vs. BE)
Metro 1-0 (1-0 vs ACC)
Big West 1-0 (1-0 vs. ACC)
MWC 0-1 ( 0-1 vs. SEC)
CUSA 0-1 (0-1 vs. B12)
Under current foreseeable realignment it would look like this for NC titles
1st ACC-10 (Louisville 1986, Duke 1991, 1992, North Carolina 1993, Duke 2001, Syracuse 2003, North Carolina 2005, 2009, Duke 2010, Louisville 2013
2nd SEC-6 (Arkansas 1994, Kentucky 1996, 1998, Florida 2006, 2007, Kentucky 2012)
3rd B1G-4 (Indiana 1987, Michigan 1989, Michigan State 2000, Maryland)
4th American-3 (Uconn 1999, 2004, 2011)
t.5th Big XII-2 (Kansas 1988, 2008)
t.5th Pac-12-2 (UCLA 1995, Arizona 1997)
t. 7th Big East-1 (Villanova 1985)
t. 7th MWC-1 (UNLV 1990)
Championship game appearances
1st- ACC- 14( 86x2, 90, 91, 92 ,93, 94, 99, 01, 03, 04, 05, 09, 10, 13) 5 teams Duke, Georgia Tech, Louisville, North Carolina, Syracuse
2nd B1G-10 ( 87, 89, 93, 00, 02x2, 05, 07, 09,13) 6 teams Illinois, Indiana, Maryland Michigan, Michigan
State, Ohio State
3rd SEC-9 (94, 95, 96, 97, 98, 00, 06, 07, 12) 3 teams Arkansas, Florida, Kentucky
4th Big 12- 6 (88x2, 03, 08, 12) 2 teams Kansas, Oklahoma
t.5th Pac-12 5 (95, 97, 98,02, 06) 3 teams Arizona, UCLA, Utah
t.5nd Big East- 5 (85x2, 89, 10, 11) 4 teams Georgetown, Villanova, Seton Hall, Butler
7th American-4(99, 04, 08, 11) 2 teams UConn, Memphis
8th MWC-1 (90) UNLV
It appears college basketball is about to become the ACC vs. B1G for dominance and the SEC will always be top heavy with Kentucky, Florida, Arkansas, Big XII will always rely on Kansas, and the Pac-12 will be decent as well. Big East is positioned to remain a good conference, but will not be the juggernaut it was before.
From 1985 until 2013 17 teams and 8 conferences have won a national title
1st ACC-8 (Duke 1991, 1992, North Carolina 1993, Duke 2001, Maryland 2002, North Carolina 2005, 2009, Duke 2010)
t.2nd SEC-6 (Arkansas 1994, Kentucky 1996, 1998, Florida 2006, 2007, Kentucky 2012)
t.2nd Big East-6 (Villanova 1985, UConn 1999, Syracuse 2003, UConn 2004, 2011 Louisville 2013)
4th B1G-3 (Indiana 1987, Michigan 1989, Michigan State 2000)
t.5th Big XII-2 (Kansas 1988, 2008)
t.5th Pac-12-2 (UCLA 1995, Arizona 1997)
t. 7th Metro-1 (Louisville 1986)
t. 7th Big West-1(UNLV 1990)
Championship game appearances by each conference in the last 29 years( Big 8 counts as Big 12 and I am counting Memphis and Michigan)
1st- 13 ACC- (86,90,91,92,93, 94, 99, 01, 02, 04, 05, 09, 10) 4 teams Duke, Georgia Tech, Maryland, North Carolina
2nd Big East-10 (85x2, 87, 89,96, 99, 03, 04, 11,13) 6 teams Georgetown, Villanova, UConn, Seton Hall Syracuse, Louisville
t.3rd SEC-9 (94, 95, 96, 97, 98, 00, 06, 07, 12) 3 teams Arkansas, Florida, Kentucky
t.3rd- B1G-9 ( 87, 89, 93, 00, 02, 05, 07, 09,13) 5 teams Illinois, Indiana Michigan, Michigan State, Ohio State
5th Big 12- 6 (88x2, 03, 08, 12) 2 teams Kansas, Oklahoma
6th Pac-12 4 (95, 97, 02, 06) 2 teams Arizona, UCLA
7th Horizon-2 (10, 11) 1 team Butler
t.8th MWC-1 (98) Utah
t.8th CUSA-1 (08) Memphis
t.8th Metro-1 (86) Louisville
t.8th Big West (90) UNLV
Conference records in the championship game
ACC 8-5 (5-0 vs. B1G, 0-1 vs. SEC, 0-2 vs. BE, 1-0 vs. Pac-12, 1-0 vs. Horizon, 1-0 vs Big XII, 0-1 vs, Metro, 0-1 vs. Big West)
SEC 6-3 (1-1vs. B1G, 1-0 vs. ACC, 1-0 vs. BE, 1-2 vs Pac-12, 1-0 vs. Big 12, 1-0 vs. MWC)
B1G 3-5 ( 0-4 vs. ACC, 1-1 vs. SEC, 2-0 vs Big East)
Big East 5-3 ( 1-1 vs. Big East, 2-0 vs. ACC, 1-0 vs. Big XII, 1-0 vs. Horizon, 0-1 vs. SEC, 0-2 vs. B1G)
Pac 12 2-2 (2-1 vs. SEC, 0-1 vs. ACC)
Big 12 1-3 ( 1-1 vs Big 12, 1-0 vs. CUSA, 0-1 vs. BE, 0-1 vs. SEC)
Horizon 0-2 ( 0-1 vs. ACC, 0-1 vs. BE)
Metro 1-0 (1-0 vs ACC)
Big West 1-0 (1-0 vs. ACC)
MWC 0-1 ( 0-1 vs. SEC)
CUSA 0-1 (0-1 vs. B12)
Under current foreseeable realignment it would look like this for NC titles
1st ACC-10 (Louisville 1986, Duke 1991, 1992, North Carolina 1993, Duke 2001, Syracuse 2003, North Carolina 2005, 2009, Duke 2010, Louisville 2013
2nd SEC-6 (Arkansas 1994, Kentucky 1996, 1998, Florida 2006, 2007, Kentucky 2012)
3rd B1G-4 (Indiana 1987, Michigan 1989, Michigan State 2000, Maryland)
4th American-3 (Uconn 1999, 2004, 2011)
t.5th Big XII-2 (Kansas 1988, 2008)
t.5th Pac-12-2 (UCLA 1995, Arizona 1997)
t. 7th Big East-1 (Villanova 1985)
t. 7th MWC-1 (UNLV 1990)
Championship game appearances
1st- ACC- 14( 86x2, 90, 91, 92 ,93, 94, 99, 01, 03, 04, 05, 09, 10, 13) 5 teams Duke, Georgia Tech, Louisville, North Carolina, Syracuse
2nd B1G-10 ( 87, 89, 93, 00, 02x2, 05, 07, 09,13) 6 teams Illinois, Indiana, Maryland Michigan, Michigan
State, Ohio State
3rd SEC-9 (94, 95, 96, 97, 98, 00, 06, 07, 12) 3 teams Arkansas, Florida, Kentucky
4th Big 12- 6 (88x2, 03, 08, 12) 2 teams Kansas, Oklahoma
t.5th Pac-12 5 (95, 97, 98,02, 06) 3 teams Arizona, UCLA, Utah
t.5nd Big East- 5 (85x2, 89, 10, 11) 4 teams Georgetown, Villanova, Seton Hall, Butler
7th American-4(99, 04, 08, 11) 2 teams UConn, Memphis
8th MWC-1 (90) UNLV
It appears college basketball is about to become the ACC vs. B1G for dominance and the SEC will always be top heavy with Kentucky, Florida, Arkansas, Big XII will always rely on Kansas, and the Pac-12 will be decent as well. Big East is positioned to remain a good conference, but will not be the juggernaut it was before.