The Iron Giant.
How about some oldies but goodies from Terry Gilliam:
Time Bandits
The Adventures of Baron Munchausen
other older fantasy films. The Princess Bride has already been mentioned, but how about** Krull** or the Neverending Story?
If you think she’d like them, maybe Ace Ventura, Pet Detective (well, there are some sexual jokes in both films, might want to preview them before you give parental approval).
You might want to look up the word “inappropriate.” You appear to not understand its meaning.
Trying to think of some that I liked as a kid that haven’t been mentioned…
You’ve mentioned that you’ve done Star Wars, LOTR and Harry Potter…what about Indiana Jones? Raiders was my favorite movie as a kid.
Light Comedies:
Home Alone
Uncle Buck
Who’s Harry Crumb
There are a bunch of old 70’s Disney movies along the lines of The Love Bug…
Parent Trap (both versions)
Freaky Friday
Bedknobs and Broomsticks
Chitty Chitty Bang Bang
Mary Poppins
Then non Disney Freaky Friday type ripoffs - (kid as an adult or switching bodies)
Like Father Like Son
Big
13 Going On 30
Vice Versa
I don’t know how much a girl would like them, but all of the Ray Harryhausen moves
Clash Of the Titans
Jason and the Argonaughts
Sinbad
I second the suggestion of Matilda. It is perfect for an 8 year old, though it may be a trifle scary in places.
My 8 year old son loved it, I think a girl that age would love it even more - the heroine is after all a spunky little girl.
Edit: forgot to add that adults can enjoy it as well. I did.
One of the things we really enjoyed (As did my boys of that age at the time) were any of the Hayao Miyazaki movies. Most have a really good message, have a strong female character, and have nuanced levels of humour like the best Looney Tunes cartoons. Who Framed Roger Rabbit would get my vote as well.
A more recent one that my daughter really really loves is Because of Winn-Dixie. She can’t get enough of that one.
Thank you Ellen Cherry.
My first thought was The Secret of Roan Inish.
The Journey of Natty Gann.
Duma
Miss Minnoes (I can’t look up spellings or link right now. This has Carice van Houtin in it, as a cat who can turn into a woman and she switches back and forth to help solve crimes. It’s delightful.
Dear Frankie… I just watched this with my daughter (11) and she loved it.
Ones I haven’t seen mentioned - National Velvet, Around the world in 80 days, Old Yeller, Shaggy Dog, Swiss Family Robinson, Gullivers Travels, Little Women, Dr. Doolittle, Pippi Longstocking, Herbie movies,
The Last Unicorn, Black Stallion, Black Beauty
Extra votes for Princess Bride, Neverending Story, Bedknobs and Broomsticks and The Secret Garden.
Also, if you can find them, old Carol Burnett show episodes. Tim Conway is hilarious at most ages but I find kids around that age just get his humour.
My older kids and I enjoyed A League of Their Own (I was in fact amused that they were so young that any time Tom Hanks appeared somewhere they’d say, “there’s Jimmy Dugan!” 
) It’s a little racy but nothing that kids are going to really pick up on much, and it’s a good story. Sadly I had it on VHS and haven’t picked up a DVD. Maybe it’s on Netflix.
If you don’t mind some cusswords, much of the oeuvre of one Jim Carrey is delightful for the 8-year-old. Mine (a boy) likes Liar, Liar and Bruce Almighty. Re: Jimmy Dugan above, he will say, “hey, it’s God!” with a smirk when he sees Morgan Freeman.
We also enjoyed all the Back to the Future and Bourne movies together, along with the aforementioned Indiana Jones series.
Dr. T is played by Hans Conried, who, among many other things, voiced Snidely Whiplash in Dudley Do-Right and Captain Hook in the Disney Peter Pan.
All the Miyazaki movies!
For her age, My Neighbor Totoro, Kiki’s Delivery Service, Arrietty and Ponyo are MUSTS.
Extra bonus, you’ll love them too.
I love the Court Jester.
Jumanji?
Also from Studio Ghibli (though not Miyazaki), my highest recommendation goes to Whisper of the Heart; both my daughters adored it at that age and continue to watch it regularly. It’s quasi-sequel The Cat Returns is pretty good too.
The Wizard of Oz.
You have probably seen it already, but I just saw Frozen. (My youngest is in his third year in college.) I enjoyed it thoroughly. Probably the best thing Disney has done since Lion King. (Tangled wasn’t bad, either.)
Kit Kittredge or Nims Island?
Just don’t think about timeline or events too much.