Here's why 2008's Rambo had the best iteration of Sylvester Stallone's Expendables. The image of Rambo audiences know best comes from Rambo: First Blood Part II and Rambo III. These turned the soldier into a muscle-bound, bazooka-wielding action hero capable of taking on armies single-handed. The lukewarm response to the third film, combined with action movies moving in a different direction, saw Stallone retire Rambo for the 1990s. When he finally dusted off the character's headband for 2008's sequel of the same name, the star consciously moved away from the previous sequels.
Stallone came to believe that Rambo's movie sequels glamourized war, so he wanted to make a darker war movie that also brought the character back to his depiction in the original First Blood novel. Rambo saw the titular character leading a rescue mission into Burma, and the sequel became infamous for its gory carnage and high bodycount. Despite its unflinching violence, Rambo's relentless pace and Stallone's taut direction have seen it come to be regarded as one of the best sequels.
In the aftermath of Rambo's success - which proved there was still an audience for the R-rated action fare that used to dominate during the 1980s - Stallone set about building himself a new franchise. This led to The Expendables, where Stallone's Barney Ross runs a crew of mercenaries with different skills. The original idea for the movie was to make more of a grounded action thriller, but as more icons like Dolph Lundgren and Bruce Wills were added, it morphed into an '80s love letter. The Expendables movies are guilty pleasures, but they all fall short of their potential and none compare with the movies they're homaging. Rambo itself features a prototype version of The Expendables in the mercenaries staging the rescue and in a few ways, they're still the best depiction of the concept.
In The Expendables, most of the characters are cartoonish exaggerations based on the actors playing them, best seen with Chuck Norris' Booker from the Expendables 2 (which also features Jet Li literally jumping out of the story) who is essentially a living Chuck Norris meme. In contrast, Rambo's weathered crew - consisting of leader Lewis (Graham McTavish), sniper Schoolboy (Matthew Marsden), Diaz (Reynaldo Gallegos), Reese (Jake La Botz) and En-Joo (Tim Kang) - all come across as actual soldiers. They're incredibly focused when on the job, but they're pragmatic when it comes to the danger they face too. They're not especially heroic either and ultimately are forced to fight back out of desperate survival than a moral obligation.
Rambo even forms something of a bond with Marsden's sniper, who puts his rifle to devastating use in the finale. Regardless of their rough personalities, they're brave in the face of death during the final showdown, where - unlike the actual Expendables series which rarely kills characters - some of them perish while fighting. Stallone acknowledges this in his Rambo commentary too, stating of their actions that they prove their worth because "nobody" is being paid enough to go through that level of carnage. Rambo's mercenaries feel like the darker version of The Expendables that Stallone originally had in mind, and while the resulting series was lighthearted fun, Rambo's mercs - especially the permanently angry Lewis - have a grittier edge that makes them more interesting.