Then he played Danny the drug dealer in cult smash Withnail and I and life was never quite the same again as casting agents fell over themselves to secure his talents for a host of projects. He all but recreated the role in Wayne's World 2 as Del, the seasoned roadie who helps the lads put on Waynestock and usually bores all and sundry with his tales on the road.
Brown's character came up with arguably the funniest anecdote of the Nineties while remarking about his days on tour with the Rolling Stones: "...That's why Keith Richards cannot be killed with conventional weapons." Okay, it may lose a little in translation, but Del's musings on life remain a big screen delight.
Other big budget projects such as Alien 3 and Star Wars: The Phantom Menace were balanced with small screen turns in The Ruth Rendell Mysteries and Jonathan Creek.
All helped pay the rent but one of Brown's favourite roles was playing Prince John in the 1997 TV version of Ivanhoe.
"It was, quite simply, the best part I have ever been offered on screen," he remarked in one interview. "John was a much maligned figure in English history, often compared to his brother Richard and hated by the church who wrote the first draft of history.
"I tried to redress the balance somewhat while sticking to the script and playing the bad guy. It was the most fun I have ever had as a performer."
Brown was born in Cambridge and studied law before treading the boards. Armed with a law degree, he has often been tempted to pursue a legal career - not least when the acting lark hit a rocky patch a few years ago.
He's also a keen writer, inspired by Blade Runner creator Philip K Dick, Thomas Hardy and Charles Dickens.
The latter is his favourite writer in the English language. "A deeply compassionate instinctive genius for the reality of the human condition in society," he remarks. "Funny too." Ralph has been writing since he was 29 and has penned a series of plays and an acclaimed new movie due for release soon.
New Year's Day is the tale of two 17-year-old boys who mark the new year by doing 12 dangerous tasks set for them by their friends.
The movie received much acclaim at the Sundance film festival earlier in the year and could pave the way for many of Brown's other scripts.
"They're broadly speaking about me, of course, which is to say they have emotional journeys in them which I have undertaken."
Aside from Danny and Del, no two Brown characters are ever the same. It may be his chameleon-like ability that makes Ralph such a reliable co-star, but whether boasting a shaggy mullet or close crop, Blighty's hardest working actor continues to add much much needed gravity to some often outlandish offerings.
Brown has never really starred in his own series - until now. As Miami Vice, the follically challenged star of Lock, Stock, he lends his usual degree of charm and assured skill as a villain whose path keeps crossing with wide boy Bacon and his mates.
It may have polarised the critics but, in a world where every drama seems to be politically correct, it's good to have an alternative to the squeaky clean, homogenised fare from home and abroad.