This is the bitcoin address associated with Hal Finney and his now famous first transaction with Satoshi Nakamoto on January 12, 2009.

1Q2TWHE3GMdB6BZKafqwxXtWAWgFt5Jvm3

Hal’s description of the transaction on bitcointalk.org.

When Satoshi announced the first release of the software, I grabbed it right away. I think I was the first person besides Satoshi to run bitcoin. I mined block 70-something, and I was the recipient of the first bitcoin transaction, when Satoshi sent ten coins to me as a test [bolded address]. I carried on an email conversation with Satoshi over the next few days, mostly me reporting bugs and him fixing them.

Bitcoin’s first transaction was recorded in block 170.

These addresses also received BTC from Satoshi on Jan 12 but the recipients are unknown.

13HtsYzne8xVPdGDnmJX8gHgBZerAfJGEf 
1LzBzVqEeuQyjD2mRWHes3dgWrT9titxvq 
1DUDsfc23Dv9sPMEk5RsrtfzCw5ofi5sVW 
1ByLSV2gLRcuqUmfdYcpPQH8Npm8cccsFg