Somewhere I read that it was a good thing to learn at least one new programming language every year; I think I have kept up that trend since 1992:
1992: QBasic
1993: Turbo Pascal
1994: C
1995: Delphi
1996: Java
1997: JavaScript
1998: VBScript
1999: Transact-SQL
2000: C# and Prolog
2001: C++
2002: PHP
2003: Objective-C
2004: Visual Basic.NET
2005: Ruby
And this year’s winner is: LINQ. The main purpose [...]