WPF AutoCompleteTextBox is a very simple and easy to use control for WPF. The advantage of this control is that developer can bind auto suggestion logic from ther ViewModel.

Features

Supports MVVM for suggestions.
Supports Watermark.
Asynchronously load suggestions.
DataTemplate for suggestions.
DataTemplateSelector for suggestions.
Display Loading Indicator, while loading suggestions.
Icon.

Although it is a beta version yet so there may be few bugs, but I will appreciate your suggestions.

Please send me your suggestions at deepdotnet@hotmail.com.

Below is the sample how to insert control in your view.

XAML

Edit|Remove

<wpf:AutoCompleteTextBox VerticalAlignment="Top"     Height="25"     Grid.Column="1"     Text="{Binding Path=FileName, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"     DisplayMember="FullName"     ItemTemplate="{StaticResource ResourceKey=fsTemplate}"     Provider="{StaticResource ResourceKey=fsp}" />

<wpf:AutoCompleteTextBox VerticalAlignment="Top"      Height="25"      Grid.Column="1"      Text="{Binding Path=FileName, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"      DisplayMember="FullName"      ItemTemplate="{StaticResource ResourceKey=fsTemplate}"      Provider="{StaticResource ResourceKey=fsp}" />