I got 97% Have a go. http://games.aol.co.uk/quizzes-games/?game=arkadiuminc14/a-vexillology-flag-quiz&ncid=webmail17
100%, I'm a nerd on this! Have a go at this bad lad, 134 to beat! http://www.jetpunk.com/quizzes/name-world-capitals.php
Actually is mate, I work in travel so I'm a cheat in a way, I asked my staff to do it and some of them got way under 60. Cheat on Europe by trying to think of biggest football club in that country, most of the time will be right.
I'm still pretty good on flags from the olden days of computer footy games where the only teams were internationals, with the likes of Rumberto Boggio and Dooyego Mabaronna due to a lack of licences.