Best spectre choices

I would like to create this topic to help future people:
Which are the best spectres you have used so far and thoughts about it?

1. Vaal Guard (the one with fire grenades)
The strongest i've tested until now, low cost, and has fast casting speed.

2. Cultist Archer
This one i'm enjoying the most, has two big AoE skills and can destroy screens if you manage to get some numbers.

3. Priest of the Sun
Clunky but deals some good damage with the laser beam, it has a big cooldown tho.