Woke Up Gay (or, in some cases, Woke Up Straight)
Planet Of The Leather Collars Are Perfectly Normal
Sekrit Vampires & Werewolves & Fairies, Oh My
Separated At Birth
Hello There, New Colleague- ...Last Night's Pick-Up, Fuck.
Pretending To Date For Totally Valid Plot Reasons
Makeover Shenanigans
Time Travelling Test Tube Baby Love Child

...so I got most of those from SGA, but they would all be hilarious in Smallville, or any of your fandoms.