http://www.edn.com/electronics-blogs/other/4391661/NASA-pits-Shatner-against-Wheaton-for-Mars-landing-videos?cid=Newsletter+-+EDN+Fun+Friday

Copy and paste this one for a comparative between Shatner and Wheaton with the same script for the next Mars rover, which will land on the sixth.

Personally, I prefer Wheaton's enunciation better than Shatner's. Easier to understand, y'know.