For a  student, fresh out of grad school with a Masters degree in Computer Science ,what would be a perfect first job to kick start his/her career?

Based on having been a computer journalist for 20 years, I'd say start with as big a company as you can get into--Oracle, Microsoft, SAP, Symantec, whatever--with an eye to going to a startup later. Starting with an established big company helps give you street cred when you do go to a startup. It lets you see how a big company's "best practises" in software development work. It gives you access to relationships in your own company and at others via developer conferences that you can use later if you do choose to go into a startup. In general it's easier to go to a smaller company from a bigger one than to go to a bigger one from a smaller (though smaller companies are often acquired by bigger ones). But other particularities that you didn't mention could have a major bearing on all of this. Do you care where you live? Just what aspects of computer science appeal to you the most? And which are you good at? How many hours a week are you willing to work? There are good jobs in corporate IT departments. It's always a challenge to adapt commercial software to a company's individual needs. And this would enable you to develop expertise in a product or service area that could lead to work in a startup that specializes in that area, or simply to a long, stable career with big companies working in, say, auto manufacturing, or pharmaceuticals, or bicycles (they're nearly all made abroad but a few firms are headquartered here). I suspect you need to think more about just what you can do, like to do, and will get paid to do, along with the lifestyle consequences of each career option you have.

Probably a startup. Not as much financial stability, or any other kind of stability, but you'll have more responsibility and the opportunity to do a lot more things. Fresh out of grad school means what you need most is experience, and a startup can give you more of that than a big company. Big company gives you a big name to put on your resume, which is great. But under that name it will probably say "Second Junior Assistant Associate" something, and you won't have a lot of achievements to list along with it unless you stay for a while. There will be a much more reliable promotion path and process at a big company, but that works both ways - you may know you'll get promoted in 2 years, but you know it's going to take 2 years. With a startup promotions can be kind of random, but you can rise really fast if the company grows quickly.

one that seems interesting him most... and if not possible then you should start wd best offer you can get..later on you can hop to your areas of building interests. you can start working wd some company first (you'll get payed for learning and practical experience ) and you can make up some good connections too.. rest u can figure out later