Kim Kardashian & Kanye West -- Head-to-Head in London Popularity Contest

Kim Kardashian and Kanye West are drawing HUGE crowds of adoring fans overseas on their trip to London -- but one might be attracting more fans than the other ... and you'll never guess who ...

Kim and Kanye left the Radio 1 studios in the Big Smoke yesterday -- where Kim was promoting the upcoming season of "Keeping Up with the Kardashians" -- and on their way out the crowd went wild, screaming their names and asking for autographs.

But the fans seemed to be shouting one name louder than the other -- Kim! Kim! KIM!

So we gotta ask ...