Eubank was a deserved 3-0-1, an undeserved loser to Collins (first), knocked out Graham in sparring before fighting any of them, and on a few days notice gave Calzaghe his hardest fight to date. Eubank has also the best win of all three - 118-109 against 35-0-0 G. Rocchigiani. Stats and facts don't lie.
As far as skills are concerned, probably Watson. But overall I would say they are all very close and very good.
If Watson hadn't had that collapse and had beaten eubank (which was happening) then he'd be the best. considering that eubank is seen as the best british smw (though calzaghe and froch may disagree), then watto was potentially the best british smw ever. of the others - benn acheived the highest feat calzaghe reigned the longest - the marathon man of british smw one on one eubank probably trumps it if hes fully committed Collins, though not british is surely on a pareable level to both in abilty. herolgee licks em all though
It is a toss up between Benn and Eubank. I would say Eubank just, but can understand those who place Benn first. Watson was my favourite of the three, but fate cut short his career, and although he had the potential to top both Nigel and Chris, it was sadly 'only' potential, in actuality he is behind both.