I have a very eclectic approach to collecting ancients. I have several specialist areas of collecting and then again I have several generalist areas too that lead to what appear to be themes.
I have just added a Genius reverse variety that I have been chasing for a while and thought it worth sharing a few of them.
The classic GENIO type is "Genius standing left holding patera and cornucopia". These are in general a very common type and they can be found from a nice wide range of mints. There are some scarcities within the series but most people looking for one GENIO type will likely end up with this reverse type.
Here is a scarcer example of this common type.
Maximianus Herculius, Follis
Obv:- IMP C M AVR VAL MAXIMIANVS P F AVG, Laureate, draped and cuirassed bust right
Rev:- GENIO IMP-ERATORIS, Genius standing left holding patera and cornucopia
Minted in Antioch (_ | Theta / E //ANT Dot). Early to Later A.D. 309
Reference:- RIC VI Antioch 112c (R) (Citing Oxford; Apparently a rare issue for Maximianus Herculius and only issued from this officina)
6.39 gms. 26.19 mm. 0 degrees. Better than the RIC plate coin (reverse only illustrated).
From RIC Notes "A very remarkable innovation, peculiar to this issue, is the reappearance of Herculius (with the long legend Imp C M Aur Val Maximianus P F Aug matching those of Galerius and Licinus, and with cuirassed bust) on rare coins with Genio Imperatoris; this is parallelled at the same time (see RIC VI page 656). Expelled from Italy c. April 308, and rejected at the Carnuntum conference in November 308, Herculius had received ample share in the coinage of Constantine's mints, and it seems that Maximinus (now antagonisitc to both Galerius and Licinius) may have been momentarily willing to demontsrate his hostility by including the name of the man who might still play and anti-Galerian part in the west."

A variation on this type is the addition of a flaming alta,r into which the libations are being poured.
Galerius - Follis
Obv:- IMP C GAL VAL MAXIMIANVS P F AVG, Laureate head right
Rev:- GENIO IMPERATORIS, Genius standing left holding patera over lighted altar
Minted in Antioch (Creascent | B / ANT). A.D. 310-311
Reference:- RIC VI Antioch 148a
Flan flaw on bust

This is my newest addition. A variation where the patera has been replaced with a Victoriola. This type is generally quite scarce.
Licinius I - Follis
Obv:- IMP C LIC LICINNIVS P F AVG, Laureate head right
Rev:- GENIO AVGVSTI, Genius, nude but for a chlamys hanging low from his left arm, modius on head, standing facing, head left, holding up a figurine of Victory in his righ hand and a cornucopia in his left arm
Minted in Antioch (* | H // ANT). A.D. 311-312
Reference:- RIC VI Antioch 162a (S)

The Victoriola type occurred briefly before the transition to the head holding types.
Maximinus II Daia - Follis
Obv:- IMP C GAL VAL MAXIMINVS P F AVG, Laureate head right
Rev:- GENIO AVGVSTI, Genius standing left, modius on head, naked but for chlamys at waist, left hand holding cornucopiae and right hand holding head of Sol
Minted in Antioch (* | E/D / ANT). A.D. 312
Reference(s) - RIC VI Antioch 164b
Flan flaw on eye of bust on pbverse otherwise a pleasing example

This type is contemporary to the Sol holding Serapis head type.

And at about the same time Alexandria is producing a Genius holding Serapis head type.
Maximinus II Daia - Follis
Obv:- IMP C GAL VAL MAXIMINVS P F AVG, Laureate head right
Rev:- GENIO AVGVSTI, Genius, naked but for chlamys fastened at his right shoulder and hanging from his left shoulder, standing facing, head left, wearing modius, holding head of Serapis, which faces him, in right hand and ornate cornucopia in left arm behind
Minted in Alexandria (* / N / Branch | B / ALE). A.D. 312-313
Reference:- RIC VI Alexandria 160b

Anyone have any other LRB GENIO variations?
Martin