As part of the VS2008 install Visual Studio will migrate all your old VS2005 settings. This is a bit of a problem if, like me, you have Resharper installed. Resharper disables Visual Studio’s intellisense in favour of its own. This wouldn’t be so bad except VS2008 doesn’t bring Resharper with it (Resharper for Visual Studio 2008 is coming but won’t be in beta till the new year). So when you start to type in VS2008 you suddenly realise that intellisense has gone (and realise that you can’t remember anything any more without it).
In order to restore your crutch pull down the Tools menu and choose options. Expand out Text Editor and highlight C#
Now make sure the statement completion settings are as shown above; with "Auto List Members" and "Parameter Information" checked. Ah that’s better, I don’t have to think as much! Now if only Jetbrains could hurry up then I could think even less!