I had seen a bunch when I first saw it, but last night I watched it for the 2nd time since it came out and the mistakes are too numerous & distracting.
PLOT HOLES
1. Melvin & Carole (Nicholson & Hunt) kiss in the middle of the movie and they both enjoy it. At the end, they kiss and it's terrible. They both act like it's the first time they ever kissed and that if it's going to be like this, that the relationship might not work. They kiss again and this time, everything's enjoyable as if it's a surprise... when they kissed way before and it was great.
2. Melvin won't let anybody in his apartment or disrupt anything, yet leaves the key to some guy he barely knows, Frank (Cuba Gooding Jr.), and has Simon's stuff all brought in?
3. Melvin's banned for life from the restaurant by the owner who threatens to even use the police officers eating a few tables away to remove him by force, yet he's eating there about 20 min later within the movie.
4. Camera pans throughout the hotels room where we see dozens of highly detailed gorgeous sketches of Helen Hunt naked, when she *now* says "Now we're being naughty, pal." after which Simon then says he can't get the angle to sketch properly because of his cast?
And there are plenty of scenes have continuity errors, such as when the camera angle changes mid-scene, people are in different positions, either holding something they weren't or vice-versa, etc. Really, REALLY blatant stuff like this throughout the movie.
Dialogue that is happening onscreen that we can't see who utters the words, really blatantly obvious dialogue replacement when a character is off-screen, and awkward scenes such as when Melvin leaves his shrink, utters the film's title after which we hear a concerned "Oh" from somebody off-screen and we see a room filled with patients who are ignoring Melvin as he walks out. Makes zero sense.
It's a great fun film, but these plot holes & mistakes are the most blatant I've ever seen. Strange that a movie with a high-profile cast & director would end up looking like such a hack job.
NOTE : What was weird was seeing the 2 actors in a restaurant sitting at the same table who ended up playing Dr Cutty & Dr Taolb in House. That was pretty strange.
"As Good As It Gets" = worst mistake-filled movie ever? 
