Here are some unique and/or rare pins that I remember playing during my last PAPA visit:
Varkon (rare & unique pinball disguised as arcade machine, only 90 ever made):
http://www.ipdb.org/machine.cgi?gid=2721
Safecracker (unique w/ interactive board game in the backbox):
http://www.ipdb.org/machine.cgi?gid=3782
Banzai Run (unique w/ vertical upper playfield):
http://www.ipdb.org/machine.cgi?gid=175
Cactus Canyon (kind of rare, last traditional Bally/Williams pinball ever made):
http://www.ipdb.org/machine.cgi?gid=4445
Also, if you liked TOTAN, be sure to check out Theatre Of Magic (http://www.ipdb.org/machine.cgi?gid=2845) and Cirqus Voltaire (http://www.ipdb.org/machine.cgi?gid=4059) as they were designed by the same dude, John Popadiuk.
These were all up & running on all 3 days during my last PAPA visit, so you should definitely have a chance to play them. Check 'em out!