If you want to optimize for the smallest possible memory footprint and you don't mind jumping through a bunch of hoops that the .NET CLR was invented to take care of for you, then writing a direct Win32API app and hooking to GDI+ is the way to go. Petzold was the definitive reference.
Really, though, it's sort of a fool's errand, since the .NET runtime is going to be loaded into the OS's memory whether your app uses it or not, so you may as well link to it.
