These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Fridge Brilliance: Why did Zoil stick with two clearly incompetent agents and give them as little information as possible? Because he was deliberately trying to sabotage the Big Guy's efforts to track down Paul.
Clive mentions that the last time he had sex before meeting Paul was with a woman cosplaying as an Ewok.
"Clive likes boning space bears!"
Our Man In Black makes his first appearance and, whilst looking serious and professional, performs the The Ketchup Test on a puddle of liquid on the ground... remember when Clive pissed himself when he passed out earlier?
Ugly Cute: Paul is basically a Grey with puppy dog eyes and a myraid of facial expressions due to his personality.
What Do You Mean, It's Not for Kids?: Honestly, if you've been to the theater and seen this film, count the number of little kids you see. Clearly parents see the wide-eyed, cute looking alien in the commercials and, despite the R rating, feel it's totally cool to take the young'uns.
There were even some cases in the UK where the trailers played before kids' movies.