I am against Internet Polls because most of the voters were born in the 1970s an 1980s and most of them do not know much about the clubs history. For example Eric Cantona was voted Man U's best ever player ahead of Bobby Charlton or George Best in Man U's poll and having seen all 3 players on tv or at BDTBL (and Old Trafford), I would say Cantona isnt as good as Best or Charlton.
I have a keen interest in Blades history so I would say that Ernest Needham is our greatest ever player, John Harris our greatest ever manager (our first manager was Teddy Davison in 1932) and our best ever season is the most difficult choice (1897-98, 1898-99, 1899-1900, 1901-02, 1914-15, 1924-25, 1925-26, 1952-53, 1960-61, 1961-62, 1970-71, 1974-75, 1989-90, 2002-03 and 2005-06 are my candidates). You may wonder why 1899-1900, 1925-26 and 1961-62 are amongst my candidates. Our points total in 1899-1900 was higher than in 1897-1898 (we won the league) but we finished 2nd as Aston Villa did even better than us that season. We scored over 100 league goals in 1925-26 and finished 5th in the 1st division. We finished 5th in the 1st division in 1961-62 (our highest placing from 1926 to present) and we were nominated by the FL to be in the Inter Cities Fairs Cup for the 1962-63 season (Burnley who finished 2nd and Everton (4th) were the other FL nominations- Spurs finished in 3rd place and their FA Cup win got them into the Cup Winners Cup) but the Inter Cities Fairs Cup Committee wanted Everton, Wendy (finished 6th) and Birmingham City (finished 20th) so after a series of meetings and disagreements it was decided that only Everton would be England's participants in the 1962-63 Fairs Cup