What I look for in a Zquest:
Can be done in less than 10 minutes in Hard Mode with just H/H.Based on this criteria, my favorites include:
Has high z-coin rewards.
Can be done easily if you know how regardless of class.
Rewards faction/reputation to advance titles that improve skills I use.
ZMissions
Grand Court of Sebelkeh - 500 lightbringer points, 150 Zcoins in 4 minutes. Set up Talkora as rayway smiter and other heroes as Discord Minion Masters.
G.O.L.E.M - 2,500 Asura points, 140 Zcoins in 10 minutes. Bring spirit spammer. The Kiln's are far enough apart that summoning spirits on one Golem Kiln won't remove the same spirit on the other one.
Against the Charr - 1,500 Vanguard points, 105 Zcoins in 6 minutes. Skip all optional steps and go south first and then straight for stronghold.
A Time for Heroes - 2,500 Dwarf points, 140 Z-coins in 4 minutes. I bring all monk heroes and use Pain Inverter, Alkar's Acid, and Finish him. Knockdown prevention or careful timing helps so your P.I. doesn't get interrupted.
Tihark Orchard - 300 Sunspear points, 80 Zcoins in 4 minutes. Once you know the mime emotes, this one is really fast.
Curse of the Nornbear - 1,500 Norn points, 105 coins in 7 minutes. You don't need the wolf "form" skill to complete the mission. Just run to the three Norn Bear summon spots.
ZBounties
Molotov Rocktail - 1,250 Vanguard, 105 Zcoins in 5 minutes. PI says hi.
Fenrir - 500 Norn points, 70 coins in 5 minutes. Skip all fights except his group.
Mungri Magicbox & Arbor Earth Call - Both give 500 Kurzick faction and 70 coins. Bring enchant strip for Mungri and PI for Arbor. I don't do the Luxon ones since I'm not working on that title.
Pywatt the Swift - 500 Asura points and 70 coins in 5 minutes.
There are a few others I always do. Which ones do you always do and why?