Exclamations I used to say:
"Big black bats!" - something to do with Batman or something?
"Great Qubits!" - I liked quantum physics, because I didn't understand it

Insults and exclamations I say now:
"Eat a (some kind of weapon)!" - Fancy way to tell someone "kill yourself". Like "Eat a grenade", "Eat a gun"
Random syllables that sound like Klingon mixed with Slavic and Hebrew - I speak none of those languages, but still say stuff like "Vzer krakh!" when I get annoyed by popups.
"Koskenkorva!" - the Finnish vodka-like drink. I don't even drink that.

Breaking the "non-religous" constraint, because i want to:
"Jesus Christ in a tank!" - In response to something very surprising that I can't remember

Saving the best for last: Captain Haddock interjections.
"Ten thousand thundering typhoons!"
"Billions of bilious blue blistering barnacles!"
"Addlepated lumps of anthracite!"
"Antediluvian bulldozer!"
"Pompous popinjay!"
"Pockmark!"