The last equality comparer implementation you'll need

PropertyEqualityComparer.cs

public class PropertyEqualityComparer<TItem> : EqualityComparer<TItem>
{
	readonly Func<TItem, object> _getter;
	public PropertyEqualityComparer(Func<TItem, object> getter)
	{
		_getter = getter;
	}

	public override bool Equals(TItem x, TItem y)
	{
		return _getter(x).Equals(_getter(y));
	}

	public override int GetHashCode(TItem obj)
	{
		return _getter(obj).GetHashCode();
	}
}