Based off having 3 jobs to pick from in the original post, I'm assuming this is three different characters working, so from my personal experience...
Easiest Giant - Altepa
Stupidly easy to get pops right in the area, and Ballistic Kick is hate reset on the target, so have a DD on the front and another on the back and play hate tennis while the WHM cures off to the side. Think of a T for how to position properly.
Easiest VNM - Brulo / Ogopogo
This is tricky because of varying factors. Brulo will eat you alive with his spikes if you're not using a good magic defense / fire affinity atma and gear, which will really strain your WHM. His Astral Flow is only 15 yalms, so your healers are always safe. Best to somehow get x2 healers for this one if possible.
Ogopogo has a nasty poison aura that does about 100 HP per tic from what I recall, and likes to spam water spells with some agas thrown in for good measure. Also can't kill him until he uses Astral Flow at 1%, giving him a bit of zombie status if he's stubborn.
If you're crazy and got some form of TH, I'd almost suggest brewing the VNMs if you got a few sets built. Repop is like 10-15 minutes now on T3s in the zones, so build a few, and just stall at a martello or flux while the rest of your pals drag them to you, as TH is the only that that affects souls dropping. Not like your cruor is getting used for anything else at this point, I'm assuming.