I like the one on the Isle of Quel'Danas where you have to convert the arcane guardians. Select the broken guardian, click the assist macro and hit '\' for my Shattered Sun-and-quest-items hotkey ... and from one to five converted guardians spring up and QuestAnnouncer shouts out. It's great when other people are around to witness it.

Ooo! My other favorite is also on the Isle, the one where you need to recharge the crystals. The collection part of this quest sucks, but the actual hitting of that '\' key is like super-chain lightning! ZAP