Anomolies from Easiest to Hardest:
1. (Faction) Burrow / Drone Collection (easiest)
2. (Faction) Hideaway / Drone Cluster
3. (Faction) Refuge / Drone Assembly (High sec)
4. (Faction) Den / Drone Gathering
5. (Faction) Yard / Drone Surveillance (Low sec)
6. (Faction) Rally Point / Drone Menagerie
7. (Faction) Port / Drone Herd
8. (Faction) Hub / Drone Squad
9. (Faction) Haven / Drone Patrol (Null sec)
10. (Faction) Sanctum / Drone Horde (hardest)

Some anomaly types may have more difficult variants (featuring elite/commander rats)
(Faction) Hidden (anomaly) - Easiest
(Faction) Forsaken (anomaly)
(Faction) Forlorn (anomaly) - Hardest

* Guristas - Kinetic & Thermal
* Serpentis - Kinetic & Thermal
* Mordus - Kinetic & Thermal
* Blood - EM & Thermal
* Sansha - EM & Thermal
* Angel - Kinetic, EM, Thermal & Explosive
* Mercenary - Kinetic, EM, Thermal & Exp

Hammer / Ther
Infilt / EM
Valk / Exp
Vespa / Kin