One From Every Country
(or more correctly, one from every sub-entity!)
An example for each of the 1048 (of 1086) coinage types in my definitive 20th Century OFEC Collection
Note that they are in the same order as on the "20th Century OFEC Entities" page.
(I am in the process of adding images of each coin, please bear with me; in the meantime - get in touch!)

#	Sub-Entity Name	coins from	coins to	Political Designation	ruling authority	Den.	Unit	A.D. Year
0577	Malaya and British Borneo Dollar	1953	1962	Monetary Union	Elizabeth II	50	Cents	1961
0578	Malaysia	1967	1988	Monarchy, Federal Elective Constitutional		20	Sen	1981
0579	Malaysia	1989	2000	Coinage Reform		1	Sen	1999
0580	Maldives	1900	1902	British Protectorate (Sultanate)	Muhammad Imaaduddeen VI	4	Lariat	1902
0581	Maldives	1913	1913	Ruler Change	Muhammad Shamsuddeen III	1	Larin	1913
0582	Maldives	1960	1979	British Protected State (Sultanate)	Muhammad Fareed Didi	10	Laari	1960
0583	Maldives	1982	2000	Second Republic		1	Rufiyaa	1996
0584	Mali	1961	1961	Republic		25	Francs	1961
0585	Mali	1975	1977	Coinage Reform		100	Francs	1975
0586	Malta	1866	1888	British Colony	Victoria	1/3	Farthing	1868
0587	Malta	1902	1902	Ruler Change	Edward VII	1/3	farthing	1902
0588	Malta	1913	1913	Ruler Change	George V	1/3	farthing	1913