This is the most comprehensive all-time Bitcoin price history chart you will find online. Updated daily. The chart is interactive:
On 2009-10-05 the market price of Bitcoin is first established at $0.000764/BTC by New Liberty Standard, the first Bitcoin exchange ($1.00 buys 1309.03 BTC.) The exchange rate history is available at two archived pages: first, second. Their last known exchange rate is $0.005472/BTC on 2010-03-02.
On 2010-04-25 the market price is established again at $0.003/BTC, using the daily volume-weighted trading price of the second Bitcoin exchange, BitcoinMarket.com (PayPal USD trades). The owner, dwdollar, actually started operating it on 2010-03-17, however trading data for the first few weeks is—to my knowledge—not available.
After 2010-07-18 the exchange rate is from the CoinDesk BPI v1 API (https://api.coindesk.com/v1/bpi/historical/close.json?start=2010-07-18&end=2022-05-17).
After 2022-05-18 the exchange rate is from the CoinDesk BPI v3 API (https://www.coindesk.com/pf/api/v3/content/fetch/chart-api?query=...) because v1 has gaps in the data starting on that date.
All above comes originally from (and is still up-to-date at) bitcoin.zorinaq.com/price. Thank you, Marc!
See the diff between Zorinaq's data and this site.
The notable change compared to the original is that two ancient datapoints were added and they show that the genesis block was mined on 2009-01-03 and until 2009-10-04 (the day before the first real price is recorded on this chart) the price was zero. This change also nicely offsets the Y-axis values of the logarithmic chart making it much more human-readable.
All the sources and the data used to generate this site are kept in a git repository on Github.
See also following variants: