I use two...v3arcade and ibProArcade, both heaviliy modified:
v3Arcade
www.bowlandcentral.com/forum/arcade.php
ibProArcade
www.bowlandcentral.com/forum/ibproarcade.php
I coded some pages to help merge the two together to some degree, such as a latest scores page that covers both:
http://www.bowlandcentral.com/forum/latestscores.php?
And also a leaderboard that covers both:
http://www.bowlandcentral.com/forum/leaderboard.php?
There is also a Chatbox (not coded by me, but certainly modified) that only logged in users can see, it appears at the top of every arcade page (but nowhere else on the forum), meaning that there is still some community 'posting' goes on, even among those who are only interested in the games.
Arcades are still a significantly popular part of my site and the people that use them will simply manually enable Flash in their browsers when the browser makers start disabling it by default.