From the musical episode “Once More, With Feeling.” Buffy’s Watcher, Giles, more recently known as the ex-husband in Ted Lasso, is played by actor/singer Anthony Head, younger brother of Murray Head.

O’Neill: “Teal’c, what is that?” Teal’c: “It is a Gua’uld long range visual communication device, somewhat like your television, only much more advanced.” O’Neill: “Huh. Think it gets Showtime?”

(SG-1 was originally on Showtime before moving to what was then the Sci Fi Channel.)

I must have forgotten about this one. 😀 I can’t actually recall others beyond the whole Wormhole X-Treme thing.