Caverns of Time - Old Hillsbrad Foothills (Key of Time - Keepers of Time Revered)
Difficulty: 3/5 to 4.5/5 depending onwow gold group setup.
Basics: Basically, bring a rogue. Just do it. First of all, the last boss drops a lot of shiney rogue loot, and anyone who's been here without will be screaming "Oh no it's the patroooll!" in his or her sleep and then fall down on the pillow, unconcious. Seeing as you need to place the bombs in the keep, and the patrols that are walking around summon two non-CCable elites while not CCable themselves - and they hit HARD - and spawn within 5 minutes again - you will want a rogue to do this solo. Have the group leader mark all the patrols so you can easily see them coming, even through walls.

Then, have the rogue put down all the bombs while the group enjoys Hillsbrad FM; afterwards, all the scary patrols will despawn and the groups that were in the houses go outside, and will thus make for easy pulling of them and Lieutenant Drake. If you haven't got a rogue, be really careful with the groups, pull them to a safe spot where you kill them - folks here hit harder than you may think, but the mobs are wow goldkitable and CCable, so do it. After Lieutenant Drake, and when you get to Thrall, be sure to let Thrall tank one or two mobs, as he can take quite a few hits. Be sure to CC the Mages as good as you can, seeing as otherwise they will CC you ;) After Skarloc, and when you enter Tarren Mill, be sure to stay outside the barn, as fighting inside it can be horribly annoying.