Hal Finney is the type of legend that we could never do justice in a short paragraph and we implore you to check out his Wikipedia and some further reading.
In short, Hal was Bitcoin’s earliest adopter and the recipient of this first Bitcoin transaction from Satoshi. He also contributed to some early debugging of the Bitcoin code and was held in high regard by Satoshi himself. We would say with certainty that Bitcoin would not be where it is today without Hal Finney.
Before that, Mr. Finney was an early, notable advocate of cryptography and is considered a cypherpunk. After graduating from Caltech he went on to work as a game developer and contributed to many notable Atari video games.