Again, that really depends on the definition. What's yours?
I would go National Championships #1, consistent relevance #2, relative recency #3. UCLA hasn't won the National Championship since 1995, but for some reason, they have never "gone away", even though their heyday was in the 60s and 70s, not recent at all. They are UCLA - the best in the West - I'm envious that Villanova has beaten them multiple times, blowing them out on their court and on National TV at least once. I felt the same thing about Villanova/Kansas until we finally beat that big, stupid bird. UConn played UCLA once, their aforementioned NC year in 1995, and they outran us in the Elite 8, despite 36 from Walter Ray to end his sophomore year. Conversely, no disrespect to them, and they could turn it around at any time, and good luck to their meteoric football team in my humble opinion, Indiana's blue-bloodedness began to fade right about when UConn's began to form despite their 3+ National Championships before the UNLV/Duke/NC/Fab 5/Arkansas era - the early to mid-90's. Michigan and Michigan State have been close, especially MSU with all those and only 2 Natty's, one of which being Magic's defeat of Bird's team, but in my humble opinion, to be a BB, you should have 3+ now, 1 of which that comes since the last 30 years. Villanova clears that hurdle, but even Kansas barely clears that hurdle. After their CONTROVERSIAL defeat of Seton Hall in 1989, if Michigan and the Fab Five had beaten Duke or NC in those back to back years and then beaten Louisville in 2013 or Villanova in 2018, Michigan would supplant Villanova as a Blue Blood, but they did not. Though the bigger and better the football conference, the more they are mostly filled with teams who do not meet this standard of blue-blood, Florida is the only football school who does, whether I like it or not. Calipari was right that Kentucky is a basketball school, and if it wasn't for him trying to corner the market with "diaper-dandy" talent (and then not having them long enough to develop more than one NC team, Kentucky, even with a Tubby Smith as coach, MIGHT have won enough NCs to own the title of best contemporary basketball program over UConn, but I guess we Calipari to thank because they did not.