VB.Net or C#.Net which is best and when?

VB.Net and C#.Net both works similar in functionality as well as usage.

Depends on the application, makes difference in action. VB.Net is more helpful in all application and C# makes some difference in Component (DLL/EXE) creation/handling the same without CLR knowledge and C# works good with .Net advanced techniques such as Remoting and Web services.