What Arcade Machines were the most innovative?
One has to be Super Bug which had a technological innovation of featuring an 8 way scrolling playfield.
(http://www.rawbw.com/~delman/images/superbug_large.jpg)
I'd have to say Dragon's Lair. This was the first ever game that used laserdisc technology, which was very innovative at the time.
[center:2n3n83xm](http://i1303.photobucket.com/albums/ag160/TrekMD/RVG%20Images/Dragons%20Lair_zpsa1eh7tqd.jpg)[/center:2n3n83xm]