I found the below videos linked via the MWO forum. The Solaris VII arenas were were exceedingly characterful in MW4: Mercs, and the voice of the commentator Duncan Fisher is unforgettable.
Via Dotsusama on YouTube:
This is a collection of various outtakes and bloopers as recorded by the voice actor for Duncan Fisher (George Ledoux), the Solaris arena announcer in Mechwarrior: Mercenaries.