I respect Ramsay MacDonald the most for founding and building the Labour Party, saying no to WW1, trying to preserve peace in the years between the two world wars and having the guts to do what he thought was necessary in 1931. Even though he stayed on as premier for too long (should have stepped down in 1933 when his health and mental ability started to deterioate) and the Stresa deal with Mussolini was a bad call.
But Attlee and Wilson were of course better premiers. Since Attlee's nationalisations where bad moves in the long run I will have to go with Wilson, which is a little sad for a euro-sceptic like me