Poll is incomplete. Steyr, Caracal, Kahr, Walther, and Taurus (and I'm sure a few more) all have striker fired designs too.
That said, for the poll choices, I will admit that I've never handled nor fired an FNS or an XD. I own a Glock and M&P and have shot a Ruger SR9. Between them I prefer the M&P.
Ignoring price, between the SR9 and the Glock I'd say that the Glock is a better gun simply due to the lack of annoying features (shark-fin LCI, thumb safety, mag disconnect). If Ruger took those off I'd consider it every bit the gun that the Glock is, and even as-is I think that the annoyances are made up for by the difference in price (basically, I still think the Ruger SR9 is a better value).