Big east, or overall? You're also short changing us, because we won the last 5 of the 2011 season, so it's actually a 29-1 run.
Duke had a really good run in 99. They were 16-0 in the conference that year. They won their first 9 to start the next season. They also won their final 6 of the 98 season; so they had a stretch of 31 straight wins in the conference. They lost to Maryland, and then won 4 more in a row, so they went 35-1 at one point.
Kentucky ran the table last year, but "only" won 5 of their last 6 in 2011, so they are working on a 21-1 stretch. UConn in 98 and 99 looks like they had a 21-1 stretch as well. In 96 and 97, UK had a 22-1 stretch. In 95 and 96, a 23-1 stretch.
Maybe Kansas had a stretch? But I'm tired of looking up random teams, so...