rahul, what are you interested in?
Your project should have something to do with a topic you are interested in, that way there's a built-in motivation for you to go forward with the project. Gaming is always popular with the college crowd. You can get as complex as you like and draw in all sorts of interesting topics, AI, network communication, security, graphics and so on. I the business world, there's a lot going on with web services, AJAX, data modeling (
EJB's, Hibernate and the like). Having solved a real business problem using these technologies would look great on a resume.