Since the Bulls started their run in 1991 only the Nets and Jazz were able to make it back to the finals any time during the next three seasons (and they both did back to back). The three years after the second appearnce neither team made it out of the second round. Of the remaining years, only the Magic, Knicks, and Pistons were able to reach the Conference Finals the year after reaching the finals (and the magic and knicks missed the playoffs in the third year). Only the Pistons made the Conference finals in the second or third year after losing in the finals.
Everyone always seems to talk about how hard it is to repeat, which of course it is, but no one ever seems to mention how badly the losers perform in the following seasons. Without the recent Pistons run, championship losers would be downright awful.
1991 Lakers - lost in first round, lost in first round, missed playoffs
1992 Blazers - lost in first round, lost in first round, lost in first round
1993 Suns - lost in second round, lost in second round, lost in first round
1994 Knicks - lost in second round, lost in second round, lost in second round
1995 Magic - lost in third round, lost in first round, missed playoffs
1996 Sonics - lost in second round, lost in second round, missed playoffs
1997 Jazz - lost in finals, lost in second round, lost in second round
1998 Jazz - lost in second round, lost in second round, lost in first round
1999 Knicks - lost in third round, lost in first round, missed playoffs
2000 Pacers - lost in first round, lost in first round, lost in first round
2001 Sixers - lost in first round, lost in second round, missed playoffs
2002 Nets - lost in finals, lost in second round, lost in first round
2003 Nets - lost in second round, lost in first round, lost in second
2004 Lakers - missed playoffs, lost in first round, lost in first round
2005 Pistons - lost in third round, lost in third round, lost in third round
2006 Mavericks - lost in first round, lost in first round
2007 Cavs - lost in second round