Ryan Reynolds is the 'Merc with the Mouth', "Deadpool".

It's rather rare to get an R-rated (or 18-rated) superhero or comic-book movie these days.

Sure, there are a few that pop up every now and then (e.g. "Kingsman: The Secret Service"). But really, today's superhero movies are mostly confined to mainstream-friendly P13 movies such as those of the Marvel Cinematic Universe movies.

However this year, there's one 18-rated superhero movie that has been making a major marketing splash in terms of its outdoor advertising, trailer and viral memes.

Of course, that upcoming movie is "Deadpool", which says it will promise a fair share of "blood, violence, sex and nudity".

Anyway, while most of us are eagerly awaiting the arrival of the 'Merc with the Mouth' this 11 February 2016, let's take a look back at our five handpicked list of best 18-rated superhero movies below!

1. "The Crow" (1994)

Brandon Lee in "The Crow".

Depending on your point of view, the undead vigilante Eric Draven (Brandon Lee) could be labelled as a superhero of sorts or an anti-hero. Whichever it was, "The Crow" was a great textbook example on how to make a dark and gritty revenge movie with a Gothic undertone. The movie, of course, was remembered for Brandon Lee's tragic death during its production due to a prop gun mishap. Lee truly immortalised the role that no one else could ever come close to replicate or outdo his performance in the subsequent "Crow" movie series.

2. "Blade" (1998)

Wesley Snipes and Stephen Dorff are engaged in a swordfight in "Blade".

Long before Christopher Nolan of "The Dark Knight" trilogy and the Marvel Cinematic Universe made superhero movies as one of the most popular genres for today's generation, one shouldn't discredit the fact that it was "Blade" that helped revive the particular genre. Although, of course, some might argue it was Bryan Singer's first "X-Men" movie in 2000 that should be the one to take that credit. Directed by Stephen Norrington and written by pre-"Dark Knight" fame David S. Goyer, this blood-drenched adaptation of the low-tier Marvel Comics of the same name made no apology in the violence department. The action was well choreographed and most of all, this movie was best remembered as Wesley Snipes' finest as the titular half-human and half-vampire hunter. Watching him slay all the vampires in various gory fashion has never looked this cool with Snipes' stylish martial-art skills and great sword technique.

3. "Watchmen" (2009)

The cast of "Watchmen".

Alan Moore's hugely acclaimed graphic novel of the same name was considered as the apex of the superhero/comic-book genre. No doubt it was a huge undertaking for Zack Snyder when he decided to make this into a big screen adaptation. Those who read the graphic novel before would certainly be delighted with Snyder's largely faithful version of "Watchmen". It was stylish, sexy and yes, shockingly violent as well!

4. "Kick-Ass" (2010)

Aaron Taylor-Johnson and Chloe Grace Moretz in "Kick-Ass".

Remember the time when Chloe Grace Moretz used to be so cool? Her groundbreaking role as the masked foul-mouthed assassin, Hit Girl was one of the main reasons that made Matthew Vaughn's unapologetically violent "Kick-Ass" such a fan favourite. The action was no doubt outrageous and over the top. You know, like over-the-top Hong Kong action movie style. It's just too bad the 2013 sequel didn't quite live up to its potential. Vaughn, of course, returned to the same 18-rated genre territory in "Kingsman: The Secret Service" in 2014.

5. "Dredd" (2012)

Karl Urban in "Dredd".

Forget about Stallone's embarrassing debacle of "Judge Dredd". If you want the real deal, this is the one you should be looking for. Pete Travis' version of "Dredd" was an undeniably gritty and ultra-violent action movie that certainly pleased a lot of fanboys growing up reading the comic book series. Sure, the overall movie may have shared "The Raid"-like storytelling approach (whereby the hero had to fight his way up to the top of the building). But "Dredd" remained a technical triumph in the action department. The "Slo-Mo" sequences were especially visually captivating, as viewers got to witness some of the blood and gore in glorious slow motion. Best of all, Karl Urban pulled off a great Clint Eastwood-like no nonsense attitude as the titular character.

"Deadpool" opens in cinemas nationwide on 11 February 2016.