убраны фиксированные размеры (ну кроме круга, ну тут уж совсем с ума сойти блин, у него априори нельзя не задать размеры...), переделано под Grid и StackPanel

Lunapark/Lunapark/MainWindow.xaml

@@ -52,27 +52,69 @@
                 </EventTrigger>
             </Style.Triggers>
         </Style>
-
     </Window.Resources>
+
     <Grid>
+
+        <Grid.ColumnDefinitions>
+            <ColumnDefinition Width="103*"/>
+            <ColumnDefinition Width="184*"/>
+            <ColumnDefinition Width="194*"/>
+            <ColumnDefinition Width="189*"/>
+            <ColumnDefinition Width="180*"/>
+        </Grid.ColumnDefinitions>
+
+        <Grid.RowDefinitions>
+            <RowDefinition Height="88*"/>
+            <RowDefinition Height="57*"/>
+            <RowDefinition Height="72*"/>
+            <RowDefinition Height="72*"/>
+            <RowDefinition Height="72*"/>
+            <RowDefinition Height="72*"/>
+        </Grid.RowDefinitions>
+
         <Grid.Background>
             <RadialGradientBrush>
                 <GradientStop Color="{StaticResource whiteColor}" Offset="1"/>
                 <GradientStop Color="{StaticResource lightBlueColor}"/>
             </RadialGradientBrush>
         </Grid.Background>
-        <DockPanel LastChildFill="False" Height="50" VerticalAlignment="Top" Margin="100,0,0,0">
+
-            <DockPanel.Background>
+        <StackPanel Name="HorizontalPreviewGradient" Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="5" Orientation="Horizontal">
+            <StackPanel.Background>
                 <LinearGradientBrush EndPoint="1,0.5" StartPoint="0.5,0.5">
                     <GradientStop Color="{StaticResource whiteColor}"  Offset="0.8"/>
                     <GradientStop Color="{StaticResource lightGreenColor}" />
                 </LinearGradientBrush>
-            </DockPanel.Background>
+            </StackPanel.Background>
+        </StackPanel>
+
+        <StackPanel Name="VerticalPreviewGradient" Grid.Row="0" Grid.Column="0" Grid.RowSpan="6">
+            <StackPanel.Background>
+                <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0.5">
+                    <GradientStop Color="White" Offset="0.8"/>
+                    <GradientStop Color="{StaticResource lightGreenColor}" />
+                </LinearGradientBrush>
+            </StackPanel.Background>
+        </StackPanel>
+
+        <Grid Name="CircleLabel" Grid.Row="0" Grid.Column="0">
+            <Ellipse HorizontalAlignment="Center" Height="50" Stroke="Black" VerticalAlignment="Center" Width="100"/>
+            <TextBlock HorizontalAlignment="Center" VerticalAlignment="Center">Покатушки</TextBlock>
+        </Grid>
+
+        <Grid Grid.Column="1" Grid.Row="1" Grid.ColumnSpan="4">
+            <Border Background="LightGray">
+                <TextBlock FontSize="20" FontStyle="Oblique" TextAlignment="Center" VerticalAlignment="Center" HorizontalAlignment="Center">Лучший парк развлечений!</TextBlock>
+            </Border>
+        </Grid>
+
         <ComboBox 
+                 Grid.Row="0" Grid.Column="1"
+                VerticalAlignment="Center"
+                HorizontalAlignment="Center"
                 x:Name="ComboBoxAttractions"
-                Height="24"
+                SelectedIndex="0"
-                Width="250"
-                Margin="30, 0, 0, 0" SelectedIndex="0"
                 Background="{StaticResource controlSolidBrush}">
             <ComboBoxItem Content="Выберите аттракцион"/>
             <ComboBoxItem Content="Болид"/>
@@ -80,49 +122,37 @@
             <ComboBoxItem Content="Кораблекрушитель"/>
             <ComboBoxItem Content="Раскачатель"/>
         </ComboBox>
+        
         <DatePicker 
+                VerticalAlignment="Center"
+                HorizontalAlignment="Center"
+                Grid.Row="0" Grid.Column="2"
                 x:Name="DatePicker" 
-                Width="120"
-                Height="24"
-                Margin="30, 0, 0, 0"
                 Background="{StaticResource controlSolidBrush}"/>
+        
+        <StackPanel Grid.Row="0" Grid.Column="3" VerticalAlignment="Center" Orientation="Horizontal"
+                HorizontalAlignment="Center">
             <Label  
-                Height="24"
+                Content="Количество:"/>
-                Content="Количество:"
-                Margin="30, 0, 0, 0"
-                VerticalContentAlignment="Center"
-                />
             <TextBox
+                VerticalAlignment="Center"
+                HorizontalAlignment="Center"
+                Grid.Row="0" Grid.Column="3"
                 x:Name="TextBoxTicketCount"
                 TextWrapping="Wrap"
-                Width="50"
-                Height="24"
                 HorizontalContentAlignment="Right"
                 VerticalContentAlignment="Center"
-                Background="{StaticResource controlSolidBrush}"
+                Background="{StaticResource controlSolidBrush}"/>
-                />
+        </StackPanel>
-            <Button
+
-                Margin="30, 0, 0, 0"
+        <Button  Grid.Row="0" Grid.Column="4"
-                Height="24"
+                VerticalAlignment="Center"
-                Width="100"
+                HorizontalAlignment="Center"    
                 Content="Купить билеты"
                 Background="{StaticResource controlSolidBrush}"
-                Click="ButtonBuyTicketsClick"
+                Click="ButtonBuyTicketsClick"/>
-                />
+
-        </DockPanel>
+        <ScrollViewer Grid.Column="1" Grid.Row="2" Grid.ColumnSpan="5" Grid.RowSpan="5">
-        <DockPanel LastChildFill="False" HorizontalAlignment="Left" Width="100">
-            <DockPanel.Background>
-                <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0.5">
-                    <GradientStop Color="White" Offset="0.8"/>
-                    <GradientStop Color="{StaticResource lightGreenColor}" />
-                </LinearGradientBrush>
-            </DockPanel.Background>
-            <Grid>
-                <Label Content="Покатушки" Foreground="Black" Width="100" Height="50" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" VerticalAlignment="Top" HorizontalAlignment="Right"/>
-            </Grid>
-        </DockPanel>
-        <Ellipse HorizontalAlignment="Left" Height="50" Stroke="Black" VerticalAlignment="Top" Width="100"/>
-        <ScrollViewer Margin="100,50,0,0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
             <Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
                 <Grid.RowDefinitions>
                     <RowDefinition></RowDefinition>
@@ -133,12 +163,14 @@
                     <ColumnDefinition></ColumnDefinition>
                     <ColumnDefinition></ColumnDefinition>
                 </Grid.ColumnDefinitions>
-                <Label Grid.Row="0" Grid.ColumnSpan="3" Content="Лучший парк развлечений!" HorizontalContentAlignment="Center" HorizontalAlignment="Stretch" VerticalAlignment="Top" FontSize="20" FontStyle="Oblique"/>
                 <Image Source="static\images\american_gorki.jpg" Grid.Row="1" Grid.Column="0" Style="{StaticResource ScaleOnMouse}" Stretch="Fill"/>
                 <Image Source="static\images\cepnoy.jpg" Grid.Row="1" Grid.Column="1" Style="{StaticResource ScaleOnMouse}" Stretch="Fill"/>
                 <Image Source="static\images\kachel.jpg" Grid.Row="2" Grid.Column="0" Style="{StaticResource ScaleOnMouse}" Stretch="Fill"/>
                 <Image Source="static\images\korable.jpg" Grid.Row="2" Grid.Column="1" Style="{StaticResource ScaleOnMouse}" Stretch="Fill"/>
             </Grid>
+
         </ScrollViewer>
+
     </Grid>
+
 </Window>