My stupid views on quests:
1) Killing - I'll do, but usually get bored fast.
2) Messenger - Annoys me as I have to waste time running when I could be killing stuff.
3) Scout - Annoys me as I have to waste time running when I could be killing stuff.
4) Spy - Annoys me as I'd rather just zerge my way in.
5) Riddle - I'm too stupid for riddles so skip or search the web for the answers (which also annoys me as its wasting time I could be killing stuff.
Basically I can never win when it comes to quests - if I'm killing stuff for a while I'm bored, if I'm doing anything else I'm annoyed as I'm wasting time I could be killing stuff (oh and I usually get lost or confused). Wherever possible I choose to do instances...exp without the boredom of grinding or the confusion of questing.