Another List

Bk1: Quirrell, during Quidditch Match
Bk2: Lockhart, during the Dueling Club
Bk3: Lupin, during last full moon
Bk4: MoodyCrouch, after the Tourney
Bk5: Umbridge, veritaserum... and the end when they left..
Bk6: Snape, after the Tower, as Sev is leaving..
Bk7: .................

Time will only tell.... who will be the DADA teacher? I find it pretty interesting that Snape has protected Harry from each DADA teacher so far...