Ding ding ding - you are a winner!

Though I also speculate that it is the largest number of leading zeros for the hash of any known input.

Here is a list of the top 10 hashes to date, followed by the block number in which they appear.  It is based on the "hashPrev" values of a recent blockchain.  And of course, the first is the made-up value from the genesis block.

[('0000000000000000000000000000000000000000000000000000000000000000', -1),
 ('00000000000000001e8d6829a8a21adc5d38d0a473b144b6765798e61f98bd1d', 125552),
 ('0000000000000000629981ebad88aafb5856e6663998d1083d74008be66a384a', 133316),
 ('00000000000000011ac23090a91a9297e8cb27c6d81cea9fc429fd37468d509e', 128456),
 ('000000000000000166b3b12f3e8928897fa5241985e75a9d31945dc2d22a39c8', 130557),
 ('0000000000000001e4646f3b4841707b62ecf7412ebc0bdbd2538e745d474a79', 133047),
 ('0000000000000001f2542ad9420bb538ffebd2e872d1dcbed233d07dc5eb0e01', 132103),
 ('00000000000000022d118b8a6b54cf261f3fb854b32f57d70545ad566e4adc7f', 132750),
 ('0000000000000002739d5a374b95e8bd7f5b7c810d07407924385b2181586dc6', 131384),
 ('0000000000000002ed549896e4571ab6ec7d805741038cb8dac97d4c2917c729', 128687)]

Followup question: what is the exact input for this hash?  I guess it would be best to provide it as an easy-to-copy-paste value, i.e. in some standard encoding like base64, so it is easy for folks outside of the bitcoin community to validate it.