I use NSE Realtime data service from Http://www.market-data-provider.com which has got excellent data speed and corrected EOD data purified for splits and bonuses. I am using same to feed my Amibroker and Metastock.The data comes automatically into my software and that gives me a worry free analysis time.
They have got a Offline EOD data systme also where you can analyse when not connected to internet and works great especially when u r travelling.
They offer you 1 Min Historical Intraday Data upto 8 Years for NIFTY and many cash stocks.I have added the historical package to my Realtime Data service and this helps me in Intraday trading.
Price is also veru cheap if you compare with other providers who offer hardly 60 stocks for general Indian providers or max 200 stocks in case of international providers. Here i can get ALL NSE Cash stocks and ALL Futures.While others charge ard Rs 3500 for 200 stocks,Excellent Data service from http://www.market-data-provider.com charges only Rs 800-900 per month For 1200 NSE cash stocks & All Futures & Free purified EOD Data and Free historical intraday ieod data.
You can also take Free yahoo finance data package from them which is cheapest- at hardly Rs 199 per month.
Hope same helps!