only just discovering http://www.kinetick.com/ '10 years of historical end of day data for stocks, futures and forex, accessible 24x7' mind you, I'd be better impressed if it were 50 or even 30 years of historical data, a 10 year amount's covering very little that's happened in the markets. 1982 was one bull run start but beginning the historical data at 1970 would be preferred, the 70s were a period of the beginning of a lot of changes in many markets "Our streaming real time quote services start at only $50 per month !"
more intraday focused here, but should more like 15-20 yrs for the more popular products. Data integrity is also pretty good.
Still like PiTrading the most considering it's only $170 for 10 years of data on the entire S&P, a ton of indices, as well as a number of stocks that are no longer listed on the market. The data isn't the most accurate as it's rounded off to the nearly 100, but to get data that doesn't round off, you have to pay $1500 so the ever so slightly lower precision is definitely worth the price discount. P.S. PiTrading is in Chicago and I got my DVD with the data in about 3 days (live on the east coast).