There are several that could be considered "best". I'll start you off with one that I think is the overall best. Yahoo. This link will bring up ATT stock just change the symbol for whatever you want. https://finance.yahoo.com/quote/T?p=AI
I could rant on about the problems with Yahoo, including how frequently their data is simply incorrect, but I continue to use Yahoo more than any other source for research and StockTwits to follow stock prices throughout the day, the odd time I wish to do that.
