Looking at this topic in general way, would you rather be incredibly strong or super fast? This involves the more physical things.
I think I'd rather be stronger than faster because strength is more of a useful life tool. Sure, you may be able to run everywhere but why not take a cab?
If you look at this from an Olympic standpoint I would want speed. The strong people are the freakishly strong weightlifters. The fast people are the sprinters who are famous.
Definitely speed. If you were talking about combat reasons, definitely; as ShadowShank696 mentioned, I could rapidly inflict damage at crucial points (where strength is not necessarily most important).