Currently at the multiplex, Captain America: The Winter Soldier is reigning supreme with its record-setting April debut of $95 million. This Marvel production is the just the latest example of an interesting and rare phenomenon – sequels that are considered superior to their predecessors.

However, if you take a close look at the superhero genre – it really isn’t a rare thing. In fact, one could argue it’s the only film genre in which sequels are very often considered improvements on the original. This doesn’t hold true for comedies or horror pics or action flicks. The explosion of comic book related titles (especially in the 21st century) has produced multiple examples of this.

Before we get there, let’s take a look back. In the late 70s, Superman was a massive hit and its 1980 sequel was generally considered a worthy follow-up that wasn’t quite its equal. The same holds true for the big comic book film character of the late 80s with Batman and its 1992 sequel Batman Returns. With both of those franchises – their third and fourth entries were considered highly disappointing.

This dynamic would shift in the 21st century. When X-Men jumpstarted the genre once again in 2000, it was well-received by critics and audiences and yet its follow-up X2: X-Men United earned even greater acclaim.

We would see this happen yet again when Spider-Man 2 improved upon Spider-Man.

And yet again when The Dark Knight became a beloved global hit with most believing it reached greater heights than Batman Begins.

Marvel Studios has seen this happen with both the current Captain America sequel and Thor: The Dark World from last year. And we’ll see if their trend continues with next year’s Avengers follow-up.

As you can see, it’s usually more the rule than exception that superhero sequels are thought of as bettering film #1. You could put Blade II and Hellboy: The Golden Army in there as well, according to many moviegoers.

Having said that, it doesn’t always hold true. You would be hard pressed to find many people who believe Iron Man 2 was a better experience than the 2008 original. And while second pictures have had lots of luck, third installments in the 21st century are a different story. Spider-Man 3, X-Men: The Last Stand, and (to a lesser degree) The Dark Knight Rises were all considered letdowns. The exception is Iron Man 3, considered an upgrade over #2.

Of course, there are sequels in film history outside of the superhero genre that this applies to with The Empire Strikes Back being an obvious example. Others that come up in the conversation: Terminator 2: Judgment Day (though I would disagree), The Road Warrior, and Star Trek II: The Wrath of Khan.

As far this blog post’s focus, we’ll be seeing more examples of superhero sequels within weeks with The Amazing Spider-Man 2, the buzz of which already indicates it’s more solid than the original. And there’s X-Men: Days of Future Past, which will try to top X-Men: First Class. We will see if the usual third entry letdown occurs with Captain America and Thor follow-ups in the next couple of years.

One thing is clear – when it comes to comic book pics – the first issue isn’t always the most memorable.