Now streaming: Before he was 'Iron Man,' Robert Downey Jr. made a comeback in 'Kiss Kiss

It's hard to think of Robert Downey Jr. playing anything but Tony Stark. However, before he could reach his peak in the "Iron Man" movies, Downey had to rebuild his career.

When he was just taking off as an actor, Downey already struggled with drug abuse. The tabloid stories about what the actor ingested read like the lyrics of Queens of the Stone Age's "Feel Good Hit of the Summer" — "nicotine, valium, vicodin, marijuana, ecstasy and alcohol."

By 2003, though, that changed. Out of rehab and sober, Downey refocused on his career. By 2005, he reasserted himself in the hilarious "Kiss Kiss, Bang Bang" (now streaming on HBO Go).

From writer/director Shane Black ("Lethal Weapon," "The Nice Guys"), "Kiss Kiss, Bang Bang" is a buddy action flick atop a Hollywood noir atop a black comedy.

Downey plays a thief who is parading around Los Angeles, pretending to be an actor. Soon, he finds himself in the middle of a murder mystery involving movie moguls. To help Downey solve the case, there's his childhood crush played by Michelle Monaghan, and Val Kilmer as a gay private eye.

The trail winds and sometimes confuses, but "Kiss Kiss, Bang Bang" works because you get the sense that everyone involved has something to prove.

Audiences knew Downey could be this excitable, puppy dog of an actor with tons of personality and quick wit; we just had never seen it done as well as he did it here. Kilmer can be so good ("Heat," "Real Genius," "Top Secret!," and "Tombstone") and not so good (pretty much everything he's done from 2000 to the present). Here, you can tell he's having fun, that this movie is something he actually wants to be in.

Then there's Black, who re-emerged after a seven-year hiatus with this small movie. He pretty much defined the action genre from 1987 to 1996. He disappeared the latter year after the Geena Davis action flick "The Long Kiss Goodnight" tanked at the box office.

"Kiss Kiss, Bang Bang" wasn't the big box-office hit that Downey, Kilmer and Black needed. Downey would get that later with "Iron Man," then Black would get one by directing "Iron Man 3." Kilmer, well, he was fun in "MacGruber" at least, right?

"Kiss Kiss, Bang Bang," rather, was the small blip on the radar, where this devilish trio was telling audiences, "Yes, we're alive, and yes, we can be good at this."

Also streaming in August

ON AMAZON PRIME: "Joe" now available; "Disobedience" available Aug. 25; and "Mother!" available Aug. 26.

ON HBO GO: "Heaven Can Wait" and "The Verdict," now available.

ON HULU: "The Limey" and "The Rock," now available; "Borg vs. McEnroe" available Aug. 10; and "Role Models" available Aug. 16.

ON NETFLIX: "The Aviator," "Stripes," "Million Dollar Baby" and "The Informant!" now available; and "Hostiles" available Aug. 15.