The 40 Year Old Virgin (2005)
This comedy sleeper hit provided a major breakthrough role for Dennings, as Marla, the daughter of Catherine Keener's Trish.
When Trish starts dating Steve Carell's titular innocent Andy, Marla doesn't make things easy for them, interrupting their first attempt at coitus with a teenage rant ("It's not fair you get to have sex and I don't!"), and continuing to undermine the action-averse Andy with snarky jibes. She redeems herself when it comes to convincing her mum to salvage the relationship before the end of the movie.
Cool credentials? Starring in an Apatow hit does wonders for your comedy standing.
This drugs-and-relationships drama focuses on Chris Evan's Syd and his ex London (Jessica Biel). Syd decides to head to London's leaving party (she's moving from New York to California) with buddy Bateman (Jason Statham) in tow, in an attempt to win her back.
Statham's odd wig is more likely to stick in your memory than Dennings' character, who plays a reveller hit on by The Stath's banker.
Cool credentials? London 's not quite as cool as it thinks it is...
CSI: NY (2005)
Having already appeared in CSI , Dennings landed another role in the Big Apple-based spin-off (as a different character). She played Sarah Endecott in this crossover episode, the storyline of which began on CSI: Miami .
She faces a fair bit of questioning, with Mac Taylor (Gary Sinise) and Horatio Caine (David Caruso) on the hunt for killer who has taken out a bunch of students at a party.
Cool credentials? It's another meaty appearance in a real big-name show.
Ticking yet another huge TV series off her list, Dennings had a longer run in the hospital drama, appearing in a five-episode streak. She showed up as the girlfriend of resident Dr Ray Barnett (Shane West).
Barnett moonlighted as a rocker when he wasn't at the operating table, which must have made him damn near irresistible to an alt-chick like Dennings.
Cool credentials? Appearing in ER never harmed anyone's acting career...
Big Momma's House 2 (2006)
Yes, unfortunately you read that right, Dennings did show up in this totally unwarranted sequel to a totally unwarranted original. Martin Lawrence reprises his role as the cop who's forced to go undercover as the latex-augmented grandma.
If you care, this time round Malcolm Turner/Big Momma has to infiltrate a suspicious household as the nanny. Dennings plays the older kid, though she's in good company, with Chloe Moretz appearing as her younger sister.
Cool credentials? If you needed to ask, please leave now.
Charlie Bartlett (2007)
Anton Yelchin starred in this all-too-familiar comedy drama, which followed the exploits of a privileged high-schooler kicked out of countless private schools as a result of his get-popular-quick schemes.
Dennings plays Susan, the daughter of his new school's principal (Robert Downey Jr). There are some effective comedic moments, but the whole movie fails to live up to its intriguing premise. Dennings' natural charm manages to stand out impressively amidst some talented performers, though.
Cool credentials? If you can convince as Downey Jr's offspring you've gotta know you're doing OK.
The House Bunny (2008)
Dennings got to exercise her comedy chops to the full in this well-intentioned Playboy comedy. It's annoyingly broadly drawn, and it ain't gonna win points as a feminist text, but it's not without its charms.
That is succeeds is largely down to the supporting cast that flanks Anna Faris' ditzy Mansion-dweller Shelley in her surrogate sorority house. Dennings is practically unrecognisable as Zeta sister Mona.
Cool credentials? With a little help from Shelley, the Zetas eventually manage to discover their inner (and outer) cool.
Nick and Norah's Infinite Playlist (2008)
Perfectly tuned to Dennings' onscreen persona, this sees the actress playing it snarky, sarky and more than a little charming. The night-long romance co-stars Michael Cera in his traditional awkward geek role.
More appealing to the heart than the head, the story that links the eponymous string of hip tracks is flimsier than a CD's liner notes. Be thankful for the presence of Dennings and Cera then, who make for an endlessly appealing couple.
Cool credentials? Infinite Playlist has them in spades.
Arlen Faber (2009)
Sometimes known as The Answer Man , this quirksome dramedy casts Jeff Daniels in a similar role to his cynical academic in The Squid and the Whale . While it may lack the insight and memorability of Noah Baumbach's breakthrough there's still plenty to commend.
Daniels is the reclusive author of a world-shaking spiritual book who has to interact with the real world after an accident. Dennings energy is well-channelled into a punky bookstore worker, proving that she's more interested in focusing on smaller parts in interesting material, than chasing anything too mainstream.
Cool credentials? It's proof she ain't no sellout.
This was another of Robert Rodriguez' family-orientated projects, and it's hard to believe anyone over the age of 10 wouldn't be willing him to make Sin City 2 instead of this stuff.
The unfocused, ADHD-energy of the plot, in which dorky kid Toe Thompson discovers a wishing rock, is broken up into five 'shorts', but even in bitesize pieces this'll be testing for adults. Dennings plays Toe's older sister in a segment involving, yup, a monster bogie.
Cool credentials? Rodriguez' were fast diminishing at this point. Dennings in Sin City 2 would be an altogether different prospect though...