I don't play ironman and couldn't care less about getting achievements, but I do like that achievemens drive strategy discussions and Let's Plays. So here are some suggestions that might be fun to watch:
1421 - As Ming, own colonial nations in the Caribbean and North America east coast X provinces, and own Y provinces in Australia.
Republic of Tea - Get "Trading in Tea" as a republic
American Indians - Form Hindustan, own all colonial nations in the Americas, and no Native American states exist
Kublai's Revenge - conquer Japan as any horde.
Silk Road - Control trade in Hangzhou, Beijing, Yumen, Samarqand, and any of the following: (Persia and Constantinople), (Astrakhan, Crimea, and Constantinople), (Astrakhan, Kazan, and Novgorod), (other inland combinations flowing west from Samrqand)
Not ivory coast - get Trading in Ivory while owning no coastal provinces
Not gold coast - get Trading in Gold while owning no coastal provinces
Holding it together - As a monarchy, maintain -3 STAB and sub-50 legitinacy for 100 years without accepting rebel demands or going bankrupt