Thinking about it most of the worst stoppages I've ever seen have been in British fights, usually promoted by either Frank Warren or Mick Hennessey. Some of Tyson Fury's early stoppages were shocking, there was one against a German guy in a kilt (don't ask) which was basically the guy dropped his hands to protect his balls which Fury had hit twice & the ref stopped it. Interestingly enough a friend of mine was ringside & said ol' Mick was screaming 'just hurry the fuck up & stop it Howard'. Subtlety obviously not his strong suit

There was a Ricky Burns one against a Ghanaian guy that was a shocker, Burns had been getting a little outboxed by this guy & the first time he caught the guy Ian John-Lewis (the king of bad stoppages, see last prizefighter with him stopping Michael Grant) waved it off with the other guy wondering wtf he was up to.

I'm not sure what the worst was but the Gavin stoppage rates pretty highly for shit decisions considering he was actually throwing a punch at the time.