I usually like to play very long ME campaigns so needless to say i use auto-resolve a lot. Especially late-game when its only a grind to play every single battle.
As every one knows auto-resolve favours certain type of units over others. There are few units you ALWAYS lose in auto-resolve and hence are not recommended to be taken into army if you are gonna be AR a lot. I am gonna list a couple of my armies which you NEVER lose a unit in auto-resolve unless you are extremely out-numbered.
Lord + Runesmith + Engineer + 4-5 Ironbreakers + 4-5 Thunderers + Rest artillery (i like to take atleast 2 cannons and rest organ guns)
This army is extremely OP in auto-resolve and its also very much playable if you want to.
Alith Anar + 18 Shadow-walkers +1 siege unit for immediate siege battles.
Another extremely OP in auto-resolve. You can recruit shadow-walkers at turn 1 and you will never lose them hence you can have a max experienced army of shadow-walkers as early as turn 50. Downside is that this army is totally un-playable if you need to fight a battle. You have no armor piercing so a cavalry/armored army can wreck you pretty badly.
Units which do very bad in Auto Resolve:
All higher tier Great weapon units are not worthwhile taking as they have a very high chance of dying in game's AR. Some examples: Hammerers, Greatswords, Har-Ganeth Executioners, Depthguards, Swordmasters of Hoeth. There are a few exceptions to these however and they are Black Orcs and Chosen GW.
H.elves and D.elves full dragon and dragon + hydra stacks.
So list your doomstacks that are auto-resolve dream.