First off is Jessica Alba as The Invisible Woman/Sue Storm/Richards in the Fantastic Four film franchise(2005,'07 directed by Tim Story) as opposed to casting one of the finalist for the role,in which I mean Ali Larter.

Look out Frightful Four,Ali Larter is here to take you down!
Think about it,Ali Larter would've brought more power and strength to the role of Sue Storm than Jessica would,not saying she was a bad choice,but I'm saying is she wasn't a convincing Sue whatsoever.
Next choice for this matter would be Uma Thurman an Arnold Schwarzenegger as Poison Ivy and Mister Freeze respectfully in Batman and Robin(1997 directed by Joel Schumacher). I mean...WHAT THE HELL?! Arnold as Victor Fries,the small-framed genius that went to extreme ends to find a cure for his dying wife? Instead we get the muscle-headed big boy that cracks terrible ice-related puns whose main goal was just to encase Gotham City in never-ending ice and frost that barely gave a second though about curing Nora,even though he already had a cure on his suit for stage one of the illness. So...where's the reasoning for him becoming a bad guy in that film?

Sorry Freeze,you may have won the Animated Series an Emmy,but with that suit in this film,all you're getting is the Golden Raspberry.
Now onto Uma as Pam Isley. Personally,I think she was a little too bitchy as Poison Ivy for my tastes,and not just saying that because she pulled the plug on Nora Fries' cryogenic chamber to kill her,she just came off as bitchy all-together in the film,plus the costume wasn't too exciting well done in most spots of the movie as well.

Sorry Uma,your costume just makes you look like a bad drag queen,and it doesn't help when you have your brainless,gangrenous BDSM luchadore non-love slave behind you like that.
Well folks,I need to stand off my soapbox for a bit so I can take a breather,I'll be back for more sooner or later when I can get another roll going soon. See you soon everyone.