Mark in Thane, India said: which one is best? j2ee or .NET
It is not as simple as "better" or "worse". It depends on a lot of things and there are some things about one that are better than the other and vice-versa.
All that said... My pick between those two is J2EE, and it is for these reasons...
1) It has the most demand. Around here about 50% of the software engineer job postings are for Java/J2EE. .NET is maybe 25-30% _if_ you include legacy Microsoft technologies like original VB, Visual C++, etc, LAMP is about 10-15% and everything else is the remainder.
2) Java/J2EE is widely used on both *nix (Linux/UNIX) platforms, Mac OS X and Windows. .NET limits you pretty much to just Windows (yes I know about Mono, but there is little to no demand for it). Support for multiple platforms is important because the other platforms are growing much faster than Windows.
3) Over the next few years thousands if not millions of legacy Microsoft platform developers (VB, FoxPro and Visual C++) will be moving to .NET which will glut the market and drop salaries.
4) Development and deployment tools (like middleware servers) are less expensive for Java/J2EE and there are more choices due to the openness of the platform compared to .NET which is dominated primarily by Microsoft. Quality tools like Eclipse and JBoss are free, while most of the free stuff for .NET is cut down "trial size" versions like the "Express" series. Virtually all of the other major companies have lined up primarily behind Java/J2EE, Sun, Oracle, IBM, etc.