Microsoft has an extremely respectable collection of typographic talent, and (matter of opinion, obvs) actually has done a better job with the fundamentals of typography over the last 10 years than Apple. Microsoft: several highly credible new screen faces. Apple: Market Felt as the typeface for notes on the iPhone. Hm.
Segoe UI is so good that I have Firefox set to use only it (which of course renders this entire page meaningless for me). I can even read light text on a black background in it, which previously has always sent me scurrying for Readability.