Critics pretty universally liked the first super-hero movie of the summer, with Thor getting good buzz from most websites. More than one tossed around the phrase “Marvel Studio’s best picture to date,” which I’m not sure I agree with, but it’s a darn good movie. The characters are strong, Branagh brings good depth with his direction, and the story is entertaining with enough action thrown in to make it feel like a strong summer popcorn flick. Yet, despite all of the praise, there is one element that most critics agree doesn’t progress naturally: the romantic relationship between the title character and his would-be love interest.

Romance in comic books, particularly super-hero stories, is a natural character element. From the moment we had Superman and Clark Kent, we had Lois Lane. From the moment we had Spider-Man, we had Gwen Stacy (Mary Jane didn’t come along until later). Having a love interest for our hero grounds the hero somewhat, makes them relate-able for readers or audience members, and (most importantly) gives them something worth fighting for. In fact, I would wager that more non-comic book people could recognize hero love interests than their rogue galleries; that’s how significant a part the love interests are for a hero’s world.

What is it about super-hero movies that keep missing the mark on this essential element of the super-hero story? It makes sense when you have a Hollywood writer adapting the source material, but that’s not always the case. How is it that we can have the same people create the story for the movie that are involved in telling stories in the comic books, but the romantic angle gets missed? Whether it’s because of bad chemistry, weak storytelling, or bad acting, too often the romance suffers when the hero leaps from page to screen. Don’t believe me? Here’s a look at five movies that don’t make the romantic angle of the hero’s story work, and two that do:

Thor: It only makes sense that the movie that inspired this article would be the one to start the list. While Kenneth Branagh manages to get his actors to build substantial depth for their characters, the one thing he misses is the romantic side. Chris Hemsworth’s Thunder God undergoes a change in character, shifting from a brash, arrogant god to a humble mortal willing to sacrifice himself to save innocent lives, but we never really get a sense of attraction to Natalie Portman’s Jane. There are two very capable actors here working for a capable director, but the story doesn’t give them any reason to build a romance beyond that initial physical attraction that any woman is going to feel for someone built like Thor.

Iron Man: The relationship between Tony Stark (Robert Downey Jr.) and Pepper Potts (Gwyneth Paltrow) has always been a weak part of the Iron Man franchise in my mind, largely because RDJ does such a phenomenal job of playing the egocentric Stark. With a man so invested in himself and eventually his company, where does a woman come into play? Sure, there’s one nice scene between them in the first movie, as Pepper helps Stark replace the power source in his chest, but you could remove Pepper from the movie entirely and it wouldn’t have much of an effect. Both within the story created here and in the franchise, Pepper Potts deserves better than this.

Batman Begins: Personally, I didn’t have a problem with Katie Holmes as Rachel Dawes, the would be love-interest for Bruce Wayne (Christian Bale) if he wasn’t such a messed up kid. Enough people did have a problem with her, however, that they wound up recasting the role for the sequel. While I agree that there wasn’t fantastic chemistry between Holmes and Bale, I thought there was enough to prove the point: this was the life Bruce wouldn’t be getting because of the choices he made. Still, the chemistry was the biggest complaint of the Batman reboot and after seeing The Dark Knight I understand why this relationship was so important: we need that chemistry to connect the two characters enough to understand Bruce’s loss, and that simply isn’t in Batman Begins.

Tim Burton’s Batman: Relationship problems have plagued the Batman franchise. Before Christopher Nolan even thought about making a Batman movie, Tim Burton was having his own problems. Not only did Burton (and subsequently Schumacher) have issues with building the connection, but they continually made the mistake of letting the love interest know about Bruce Wayne’s “secret” identity. It practically became a pick-up line (“Hey baby, I’m Batman: wanna come back to my Batcave and get busy?”). The solution to why Burton, Schumacher, and Nolan had issues with this element is rather simple: Batman’s a loner. He doesn’t have a canonical love interest, other than perhaps Selina Kyle for those who count that as his great-lost-love. Forcing romance into a Batman movie without a specific purpose (like the payoff in The Dark Knight) is destined for failure if you’re being true to the character.