Best Unit to Sacrifice?

[Zwischenzug]

What is the best unit for sacrificing and building up your rare creatures? That is, best unit cost wise as I'm in impossible.

[iregev]

you should try to sacrifice without losing the units there are many ways to do it.
- Vampires and anceint vamps can restore their life back (before patch 1.7)
- sacrifice with low inteliigence + giants (who can be healed with shamans)
- double sacrifice + timeback
- sacrifice + hypnotize (or demoness seduction)

and finally you can resurrect your fallen troops with Inqusitors and spell.

[BB Shockwave]

After the 1.7 Patch, Undead and non-living creatures like Plants and Cyclopes can no longer be sacrificed (they can be gained by sacrificing another unit, though).

Timeback is a good way to cut your losses to zero with Sacrifice. Also Giants or Dragons are good candidates for Sacrifice.