I thought I would add a little progress 'chart'.
Naxxramas
Arachnid Quarter
Anub'Rekhan: Dead! Best Kill - 4 mins 6 seconds
Grand Widow Faerlina: Dead! Best Kill - 2 mins 30 seconds
Maexxna: Dead! Best Kill - 3 mins 37 seconds
Plague Quarter
Noth the Plaguebringer: Dead! Best Kill - 6 mins 10 second
Heigan the Unclean: Dead! Best Kill - 5 mins 3 seconds
Loatheb: Dead! Best Kill - 7 mins 41 seconds
Military Quarter
Instructor Razuvious: Dead! Best Kill - 3 mins 48 second
Gothik the Harvester: Dead! Best Kill - 6 mins 46 second
The Four Horsemen: Alive!
Construct (Abomination) Quarter
Patchwerk: Dead! Best Kill - 4 mins 3 seconds
Grobbulus: Dead! Best Kill - 5 mins 11 seconds
Gluth: Dead! Best Kill - 5 mins 42 seconds
Thaddius Dead! Best Kill - 6 mins 16 seconds
Frostwyrm Lair
Sapphiron: Alive!
Kel'Thuzad: Alive!