Minor changes may occur depending on Raid Leader's discretion (PUG/Guild).
ToC 10/25
1. The Northrend Beasts: Acidmaw & Dreadscale - On start.
2. Faction champions - On pull.
3. Anub'arak - When boss reaches 30%.
ICC 10/25
1. Lord Marrowgar - Pull, or when all DPS are in place.
2. Lady Deathwhisper's - After the shield is broken.
3. DBS - On pull, or on 30%, depending on raid itself.
4. Rotface - On pull.
5. Festergut - Optional, on pull. Only on low DPS raids.
6. Professor Putricide - 3rd phase.
7. Blood Prince Council - When Prince Taldaram has Invocation of Blood (Darkfallen Orb, aka the DPS target).
8. Blood Queen Lana'thel - Usually after 1st air phase. You'll have plenty of bites. 2nd option would be after 2nd air phase, but that's higher risk.
9. Valithria Dreamwalker - When healers have been to portals 4-5 times, or wait till they call for Heroism/Blood lust.
10. Sindragosa - Last phase.
11. The Lich King - On pull, and again when you know you can DPS LK for good time, if it's being slow to kill.
RS 10/25
1. Baltharus the Warborn - Pull, or after 1st repelling wave, seen it done both ways.
2. Saviana Ragefire - Optional, on pull.
3. Halion - When all are inside for phase 2, or when phase 3 starts. Seen it done both phase, personally prefer phase 2, when all are inside. This way entering phase 3 start won't sway far from 50-50%. As melees with Heroism/Blood lust will be pulling DPS while ranged DPS's are running around and applying debuffs and DoT's.