I have one machine from 68 in the collection...
quirky is how i would describe it

http://www.ipdb.org/machine.cgi?id=1774

But if you want the best game from 68 then i would recommend  a Bally game... zipper flippers are just about one of the coolest features to ever be introduced to pinball and i think 68 was just about the heyday for these.

I would almost recommend a WMS HAYBURNERS2 ... zipper flippers and great backglass animation, however, previous promises to myself prevent me from recommending a game that has NO bumpers!