Media Center
Media Center is included Home Premium and Ultimate editions. It does not have its own edition like in XP anymore. The user interface is slightly improved. Unencrypted HD cable support is now also included in the media center. Parental control is also added. This is perfect for someone who wants a media computer.
Aero Theme
You just can’t resist. The translucent effect just looks awesome. Aero comes with features like 3D flip, Live taskbar thumbnails,Windows Flip.
Aero Glass
Live taskbar thumbnails
Windows Flip
3D Flip
Sidebar
Vista Sidebar
Vista Sidebar offers quick and easy access to mini-program which are called gadgets. You can customize your sidebar by putting in your gadgets that fits you. There are a lot of gadgets out there that you can download.
Customizing or adding gadgets are so simple
Instant Search Box
Instant Search Box
Searching file in Windows Vista is made easy and fast with Instant Search Box. Files that contains parts of the keyword will appear in a matter of seconds. They are also organized into different category.
DirectX10 and Live Gaming
Me as a gamer, DirectX10 is one of the features I love. DirectX10 is part of Winodows Vista. The newer games will take advantages of DX10 for better graphic rendering. You’ll need to grab yourself a DX10 video card to get this feature. DX9 still exists in Vista and DX9 will work fine under Vista.
DX10 in Flight Simulator
Live Gaming for Windows Vista is very similar Xbox Live Service. This service will connect PC gamers to XBOX360 featuring cross-platform gaming, voice messages, ranking system and much more. Live Service uses Xbox Live account if you already have one. While silver membership is free, the gold membership cost $49 per year. The gold membership offers excellent features like cross-platform gaming.
Have I missed any features???? I hope not 
If anything comes up in my mind I will add some more.