Not saying it's the best win by a Brit but Calzaghe giving Lacy a lesson in boxing was so enjoyable to watch. I agree with the Benn McClellan shout as well. Benn's will to win and sheer guts when he was getting a right shoeing is something you don't see too often.
Turpin vs Robinson wasn't that brilliant a fight but as a spectacle it was the greatest British sporting event ever.
I'm sorry but the style of the win has to count for a lot. I personally think Fury win over Klitchko is a bit overdone. Klit was looking old and vulnerable in his last two or three fights... and why not? The guy IS old at 39 for an elite athlete of that size, with lots of wear and tear. Klitchko has been safety first for a decade, but not impregnable before that. Brilliant, yes. But Fury was awkward, evasive, unpredictable and was younger, fresher and - key - the right size to ensure Klitchko had a miserable night. What is wasn't was a beating, a beatdown, a lesson or a masterclass. It was just a cagey well executed fight. (A boring fight by the way). Long way of saying that for me it wouldn't get near the top of the list.
Benn V McClellan. Nobody was giving Benn much of a chance but he showed his metal to stop one of America's biggest talents of the last 30 years. Tragic aftermath but still a great performance by a Brit.
Honeygan Curry and Benn McClellan would be my picks. I think SRR and Kostya were a little too past their best for their fights to pip Lloyd and Nigel's. They were both very clear underdogs and put on awesome shows that left no questions about who the better man was. If I really had to pick I would go for Benn, especially after getting knocked out of the ring in round one.
You can hardly say Froch v Taylor he was getting beat going into the last round, good win but no surprise he won he was a heavy favourite for the fight
Robinson was on a 90 odd fight unbeaten streak in a near 130-1 record, with over a decade and five more world titles to go when he fought Turpin and he was past his best?! I guess that shows how good he was! The two that I do not think have been mentioned but deserve at least one is John H climbing off the floor in the first and beating Napoles in Mexico City (although Napoles clearly had seen better days), and perhaps the only one that compares to Turpin/RobinsonI; when Ken Buchanan went to Puerto Rico and beat Laguna. {EDIT} Mr Francis beat me to it!
Benn-McClellan could have easily been a first round TKO loss for Benn with a different referee, it was very brave performance from Benn to come back and pull it off. It may well be among the most courageous performances by a British fighter but it's definitely not P4P the greatest win by a British fighter IMO.