I use Flightdiary for the most part these days. I started with flugstatistik and still use it occasionally because I have found FD's database is somewhat limited and they aren't all that great about updating it pursuant to requests (I've had issues with the FD database not having smaller regional airports in the USA and smaller defunct airlines).
Each have their pluses and minuses. FD can get unwieldy once you get a bunch of flights logged.