I can't suggest you that what you should do whether Java or .Net because both language will decide your carrier, but i can tell you there benefits and drawbacks....
Java is coming up very strongly, there are two reason of it 1) It is an open source and 2) It is an platform independent language. Community of Java is growing like any thing.... and in future it will capture 75% of software market
Where as in .Net, it is easy to learn than Java... and it is embedding many languages in it.... that's all about .Net
But this where brighter side of both language, now the hard truth about bothy which make difficult for any one to choice "which one?"
Since Java is open source, it get developed in very six months and we have to track all its new features, that makes it more difficult, secondly to learn Java one should have a good knowledge over C++ or C# language too... Java consist many different features like EJB, SERVELET, SWING Components and many more.... this make it difficult to understand the **** language.... So in the end, Java is tough than .Net but more scope than .NET.
Now it is turn of .NET, .Net came in market to give some competition to Java, and it did also, many programmers switch towards it since it is easy than Java. But Microsoft did one mistake, to make language more Superior than Java, they added many other language in it, that made it even more tougher and not only that almost every year.Net get upgrade and new version which comes to market is completely different from previous one, so the .Net programmers need to study again the same thing which they did earlier, from beginning. All this make factor makes .Net more complicated. so in last, .Net can become one of the nightmare of it programmer.
In the end, moral of the story is, it is you how have to decide which way you have to go, both are equally difficult, that is so life is all about.
But i will suggest that since you are fresher, you should get a good command over basic languages like C and C++, this two will help you life long....
Any ways.... i wish you a very best of luck for your future...
Thank-you