It was one of the best companies when led by its original founders.
Fixed it for you.:-)
That Paul Allen didn't liked to show up on newspapers doesn't mean he did nothing.
http://en.wikipedia.org/wiki/Paul_Allen says he didn't return to the company after being diagnosed with Hodgkin's in 1983. Surely you and gp didn't mean that MS stopped being one of the best companies in 1983?
I mean it is not only one man who makes the company, specially after 1983.
Depends how you define "best". For a company holding 90% of the world's desktop OS market, it's not doing so bad at all.
I don't think it would be in that position if it had to rely on Ballmer's leadership, without Gates, from the beginning.
And this was precisely my point. Ballmer would never be able to keep Microsoft's position if he wasn't groomed for the position internally, for years.