Possibly the two most famous and popular martial arts to appear in the Jin Yong canon were the Hong Lung 18 Palms and the 1 Yeung Finger Technique. Both are very well known and acclaimed "mainstream" martial arts that were featured in no fewer than four Jin Yong novels and were usually the signature martial arts of either main protagonists (i.e. Kiu Fung, Deun Yu, Gwok Jing) or Greats (i.e. North Beggar Hung 7 Gung and South Emperor Deun Chi Hing/1 Deng). Both martial arts were known to be extremely powerful, and typically, the wielders of Hong Lung 18 Palms and 1 Yeung Finger Technique were well-acquainted with one another.
For all that, however, we have never really seen a good showdown between a Hong Lung 18 Palms user and a 1 Yeung Finger Technique user. The closest we came was Kiu Fung vs. Deun Yin Hing in DGSD, but neither combatant really used his signature technique in a direct manner during that brief "duel" of theirs. Ostensibly, Hung 7 Gung and Deun Chi Hing used the techniques against one another at some point during the First Mt. Hua Sword Tournament, but that tournament occurred "off camera," with no details given.
That leaves us really wanting for a good showdown between an expert Hong Lung 18 Palms user and an equally expert 1 Yeung Finger Technique expert with both combatants using his respective technique in a direct manner against one another. It's a golden opportunity missed on multiple occassions, in my opinion.