Lowest Arduino Power consumption

Exactly. I have a table on the page I linked above. Here it is:

Type        Capacity mAH  Discharge %/month   Self discharge (uA)

CR1212            18              1                  0.250
CR1620            68              1                  0.950
CR2032           210              1                  3
NiCD AAA         350             20                 98
NiMH AAA         900             30                375
NiCd AA         1000             20                270
Alkaline AAA    1250              2                 35
NiMH AA         2400             30               1000
Alkaline AA     2890              2                 80
Li-Ion          4400             10                600

These are approximations but the general idea is that you don't need to get excited about using less than 1 uA because the battery is going to self-discharge much faster than that, particularly NiMH batteries.

To confirm MarkT's figure, if you use 1 uA then over a year that would be:

0.000001 * 24 * 365 = 0.00876 = 8.76 mAh