Jamie Hyneman and Adam Savage are known for not being friends off-set. Savage has admitted this freely, but stresses that the two of them got along well enough professionally (it was Jamie Hyneman who recommended Adam Savage as co-host in the first place) but make no effort to engage socially. He attributes this to clashing personalities rather than full-blown dislike.
Kari Byron, who joined the team in season 2, can be seen in Jamie's shop working on a computer in the first episode. Interestingly, it also happened to be her first day on the job as an intern for Jamie Hyneman.
To date (2015) MythBusters is the longest-running TV series in the Discovery Channel's history.
Jamie Hyneman and Adam Savage asked for Lucasfilm's blessing to make the Star Wars episode. Lucasfilm agreed, with some conditions. They could not animate blaster fire or light saber blades, and they could not portray characters doing anything that would violate the family-friendly nature of the series. In particular, they were told not to have any "twerking stormtroopers."