Minor spoilers follow, but nothing you won't have learned from reading the back of the DVD.
Held together by a wonderful central performance from Renée Zellweger, Nurse Betty is a dark yet deceptively good-natured comedy.
Suffering from an emotional and mental breakdown after witnessing her sleazy husband's murder, already-troubled and desperately unhappy waitress Betty becomes convinced a character on her favourite daytime soap is her long-lost fiancé and sets off from Kansas to Hollywood to find him.
Instead of making jokes at the expense of Betty's mental state, writer John C. Richards is very sympathetic, with Zellweger portraying her as a lost innocent, not entirely helpless but tragically vulnerable nonetheless. Crucially she's never really a victim despite this and while she undoubtedly suffers horribly the motives of the characters who treat her poorly are all understandable - even Greg Kinnear as the object of her deluded affections may be an egotistical, blinkered, arrogant pig but he genuinely believes that she's merely a quirky wannabe actress with bags of talent rather than an insane stalker.
The farcical ending where all the main protagonists descend on the same place (in this instance Betty's house) at the same time to have it out is as old as cinema itself but it works quite well here, even if the shift in tone is unfortunate.
Zellweger is ably supported by Kinnear and Morgan Freeman both doing solid work, and it's especially pleasing to see Chris Rock show restraint in his earlier scenes.
Not nearly as cruel as you might expect, and not at all mean-spirited, Nurse Betty - while far from being a laugh riot - is a solid entertainment elevated to something considerably more by the lead actress.