Which laptop to buy? Dell vs Lenovo vs HP


Hi,I am planning to buy a laptop (Got sick of desktop, used it for too long ;)). Since I am pursuing MCA, I'll be using it for programming mainly. My price range is Rs. 35000 but I can spend more provided I am getting something very good. Please suggest the best laptop brand (and model, if possible) keeping in mind 1. Good battery backup.2. Can run Windows 8 in near future.3. Is easily serviceable in India, New Delhi.4. Longevity.I know it's a too much to ask for but that's why I am here! I'll be happy to buy a machine that comes close to what I ask for :)Thanks for the help.