Recently, I used this .NET Metadata API. I have also written a blog post about it, that shows reading, updating, and removing the EXIF data from images using C#.
using (Metadata metadata = new Metadata("image.jpg"))
{
IExif root = metadata.GetRootPackage() as IExif;
if (root != null && root.ExifPackage != null)
{
Console.WriteLine(root.ExifPackage.DateTime);
}
}