I have been giving your question some thought. The easy answer to the question would be Fredric Caudron since he probably has the most World and European titles for most of the Small game disciplines and he is still a participating player although his involvement in the Korean professional league makes this a little less clear. It is not just about making the point, but how well you execute the point and the point's affect on the entire run.
Caudron without question is the worlds leading authority on balkline and 1 cushion
Its a damn shame he doesn't compete in it at all these days but im certain its the money
He said on his vid that 1 cushion is his favorite game
He recently played a exhibition with jean paul de bruijin a 47.1 match
He won easily which shows hes still in top form for the games
Its ok kozoom
Pre korean tour era
Next to him would be fellow belgian patrick niessen
Eddy leppens has won the European title for 47.2 as well
Rounding out the world top 5 would be dutch young phenoms raymund swertz and sam van etten
Those 2 can run out 250 at any moment
Note worthy is raul cuenca of spain as a world elite balkline player, i believe hes better than his spanish rival/friend esteve mata