Granted, Cell is fast, especially due to his Instant Transmission Technique. However, he lacks strength. I see you try to argue that the lightsaber will make up for his lack of strength. That's all assuming that the lightsaber will be as effective on Goku as it is on others, which I'm arguing it wouldn't, seeing as he takes disinigratory (real word?) attacks to the face on a constant basis.
Oh, and most people think that lightsabers can cut through anything, which isn't true (
Lightsaber - Wookieepedia, the Star Wars Wiki). Though one could argue that it would be as effective on his physical body as it would be on any other person if they so chose, but he also could erect a Ki shield/barrier. It could act as the same field which prevents damage to the hilt or user.
And if Goku somehow died, I'd place my money on Link being the hardest to take down, followed by Luke. Robin could probably...distract somebody or something, or tackle Vader in a self-less display of suicidal courage.
...To be honest, I dunno who "Slade" is, I can't find any info on him either. For all I know he's god-like. *shrugs*