What system failures have you had?

For those that spend time flying aircraft that simulate random or service based failures how many of you have had them and what were they? I’m asking because I’ve been pretty lucky until last night when I had an engine fire in the Majestic Q400. I’ve had my share of smaller issues, fire loops, SOVs, APU bleed, etc., but before this the biggest failure was a generator disconnect in the NGX.