What games directly reference at least one other pins with either visuals or sounds. Do not list stock sounds used across multiple games.
The most obvious is the Pinbot / Bride of Pinbot / Jack*Bot series. Then of course, Pinbot shows up in Taxi as a character and objective.
In Monster Bash, isn't "It's not plugged in yet" callout the same from TAF?
What are some of your favorite 'cameos' from other games?