Iron Woobie: Despite going through so much psychological trauma and suffering, Robert always gets back on his feet, even if he's fully aware the world will soon smack him back on his knees. He just embraces his predictment instead. Even when he eventually commits a suicide, he does it more out of spite than anything else.
It Was His Sled: Neville committing suicide in the final pages, after learning he is now the stuff from scary legends, not the vampires.
What an Idiot!: Neville is the last human left. He's besieged every night by seemingly endless hordes of vampires that aren't too smart or agile and are easily stopped by boarded windows, but make a lot of noise while trying to get inside, driving him nuts and not letting him sleep properly. Robert has access to all goods and materials imaginable and it's not that they are going to spoil within weeks. He has all time in the world at his disposal and construction experience. You'd Expect: Once Neville finally get a grasp of himself and stops drinking, he would simply build a wall around his property, especially since for safety he already had to burn down neighbouring houses. This would lessen the issue of all kinds of noise, provide another safety precaution and would remove the pressure on constant repairs, which obviously eat materials each time. Instead: He keeps boarding the windows again and again each day and for obvious reasons it takes a considerable effort from him to even apply basic sound-proofing, while there are still fists smashing over the boards and walls of his house. What makes it stand out so much as idiocy is the fact he never even considers it, despite having to deal with siege each night for years.
Narm: Neville tearfully begging a mannequin to say hello to him.
Narm Charm: But the context of it makes it heartbreaking.
One-Scene Wonder: She has about 1 minute and a half of screen time at the beginning of the film (and isn't listed in the credits), but Emma Thompson as Alice Krippin is so delightful you desperately want to know more about the woman who inadvertently created The Virus.
Special Effects Failure/Uncanny Valley: The zombie/vamps are pretty obvious CG. They tried using extras at first, but since it required constant hyperventilation, they were forced to use CG instead.
They Wasted a Perfectly Good Plot: The film's alternate ending comes closer to the message of the novel than the ending that made it into the movie and fills the above-mentioned plot hole, in addition to many others. It did poorly with test audiences, though, so Executive Meddling changed it to an ending that is completely different and misses the point of the entire novel, twisting the message so that it can still fit the title, but in almost the exact opposite way that the original ending fit it.