Australian Penny

Before 1910 United Kingdom currency was the official legal tender of Australia. The first Australian penny was minted in 1911.
The penny ran until 1964, when Australia stopped minting pre-decimal coins in preparation for decimalisation in 1966.
Dates not minted: 1910, 1937, 1954.
The Australian Penny is what really got me hooked on coin collecting and started me down the path of numismatics.
There are so many varieties to look out for in addition to just the year itself when trying for a complete collection such as:
- the "Indian" and "London" Obverse.
- Mintmarks in the form of "Dots" located on certain years in different positions on the reverse.
- Wide and Narrow Dates
Some are common, some are extremely rare.
I would wholeheartedly recommend the website:
TDK Australian Pre-Decimal Coins
For assistance with tracking down some of these varieties, it is an absolute gold mine of knowledge on the topic.