You're driving the Love Fist limo only to find out that it's a armed with a bomb, and the only way to not set it off is to drive fast, a la Speed, until the group finally disarms it. Hilarity Ensues.
The fact that Tommy is constantly annoyed throughout the whole mission makes it even more funnier.
Jezz: Tommy pal, you gotta save the band!
Tommy: I'm getting bored of this.
Jezz: Which wire, Tommy?!
Tommy: The green one.
You drive like a lunatic all over town, running over innocents, gun down several people including cops, SWAT teams, FBI agents, and cause massive destruction of property, all in broad daylight and in plain view of every law enforcement officer in town. You are eventually arrested, and as you emerge from the police station (minus weapons and a small bribe/fine) you can hear Rosenburg in the background, "Tommy Vercetti is an innocent man!"
Before the final mission, Ken talks about how he hates the prospect of him being a subject to Cement Shoes.
"I like fish. I love fish. I like them as pet in a bowl, or a food on a plate. But as much as I love them; I don't want to sleep with them!"
Early in the game, we usually get an inside look into Tommy's thoughts after a mission cutscene ends. Most of them are full of snark.
(Upon told on getting a suit to attend a fancy party - by Rosenberg of all people!) "Who does that guy think he is? Now I gotta dress like a chump as well as hang out with them? (Genuinely hurt) I like this shirt..."
"Great, more crap to wipe up! What did I do in a past life to deserve this?"