I would suggest Java.
Why?
1. Suitable for both computer desktop and network programming.
2. Java is multi-platform. A program written on a Windows desktop will run on a Macintosh or Unix platform, such as Linux or Sun Solaris. In addition Java provides a quick learning curve to other Java technologies, such as Java Web Server, Java Mobile and Java Embedded. Put another way Java is always Java.
3. Very secure. The Java Security Model restricts network programs (applets and JNLP) to reading from the network unless the applet has been given explicit permission via the Policy Tool for greater access to such resources as the local disk drive, the clipboard, etc. In addition the special zip files called jar files that store your Java programs can be digitally signed and verified.
4. Java is the only language with multi-threading capability built right in.
5. Java is object orientated, which mean that it supports the concepts of inheritance, encapsulation and polymorphism.
6. Java has lots of built in classes to make your life easier. For example the javax.swing.JEditorPane will accept input of either text or HTML then parse and display this content just like your web browser does. XML can also be parsed. The java.util.Collections class provides functionality such as sorting, shuffling and finding the min and max values from a list.
7. Java provides excellent database connectivity.