Only used this product for the two-week trial as advertised, but recommended to Paul that it be put here on the site because I found it a) very reliable and b) its incredibly cheap compared to some other software packages, and a good starting point...when I say cheap I mean cheap as in only $36 a month! It's US stocks/indices only, but for the money I felt it was well worth it.
You get two weeks free on the trial but they do charge you for some exchange fees which they dole out at $3 for the fortnight. The package runs the usual array of options for charts (c/sticks, ohlc etc etc) and a good array of indicators, too. You can customize the whole chart, draw trends etc etc and it is constantly updating. There is complete documentation available for download, too. During the two weeks it never let me down once, and the only reason I havent gone with them is I'm trialling another one at the moment. The only other downside is its not an asp application so you have to download it but its only about 3MB (about 15mins on a 56k connection).