It's a difficult question, since I think there are seasons when fans have just tasted a championship and expect a ton. I think that holds true for 2005-06 and 2011-2012.
Then you have teams like 2003-2004. You saw this team building and building and you just knew they were championship caliber.
Finally there are teams like 1995-1996 and 1998-1999 where you have really big expectations, but since you've never reached the Promised Land, somehow the expecations are not quite at the level of post-NC Uconn.
With that said, I think if you go by preseason expectations, the top 5 would be:
1. 2005-2006 They were ranked very high going into the season. AA type players with Gay and Williams. They only lost 2x during the regular season. Unfortunately, it was Final Four or bust for that team. Expectations met? NO
2. 2011-2012 I don't think I'm alone in thinking that there was some crazy possibility that Uconn would have another title contender. They brought in Drummond to go along with what we thought was an AA in Lamb and great supporting cast. Expectations met? NO
3. 2003-2004 Ranked very high going into the season and they barely got beat by a good Texas team in the s16 plus they had everyone returning. Expectations met? YES
4. 1995-1996 I thought this was the year they would get through to the FF. They had Ray and Sheffer back and Knight was primed and so on. They lost freaking two games all year! Two. Expectations met? NO
5. 1998-1999 This team just had something special to it and you knew it in 1997-8. They ran into a beast of a UNC team, but I would've been very disappointed if that team didn't make the FF. Expectations met? YES.
I would give 2008-2009 an honorable mention and I do think they met expectations.. Sure, I still think they could've hung with NC (much like I think 2005-2006 could've beaten Florida). I still think getting to a FF is a success.