I grew up adoring fairy tales (if you are a little bit of a snob, read: faery or faerie). From the Jewel-named Sapphire, Emerald, Ruby, etc. books to Hans Christian Andersen (or Fairy Tale Theater to the Nick Jr fairy tale cartoons), I was hooked. I have grown up trying to find the best retold fairy tales ever since, to create that world of wonder. There are some very good ones out there (bless you, Robin McKinley), some nifty short story collections (I LOVE Cockroach in Loafers, an updated version of Puss in Boots set in New York--I could look through my books for the anthology if you really want me to), as well as some really bad ones (mostly geared toward young adults because someone has decided they only deserve drivel).
Penelope is a charming fairy tale. Not overly complicated, but you won't be able to help smiling through it, unless you hate fun or expect every movie you see to eviscerate your intestines. It doesn't hurt that James McAvoy is extremely charismatic, or that leading lady, Christina Ricci is extremely likeable. There are some great supporting efforts from continually-crazy-mom Catherine O'Hara, always interesting Richard E. Grant, the ever-affable Reese Witherspoon, and the crazy-talented Peter Dinklage, among others. But don't take my word, check it out. . .
I was going to include the trailer, but all the trailers give way too much away! Sorry.