My top 4 arcade type games on the C-64 were Archon, Beach Head, Blue Max and Hard Hat Mack. Archon causing the most grief between my friends and myself. In reality, though, most of my time spent with the 64 was either getting into trouble via telnet, running a BBS or playing Infocom adventures.
Regards,
Scam
BTW, I should mention that the 64 a 128D, two monitors and several disk drives are still set up in the garage and still being used. Sometimes for a quick game, sometimes just to write a quick program to do some calculation or other, and quite often to hook things up via the User Port and a solderless breadboard. They're always fun.