My Holy Grail pin for 2010 was to collect the set (6x) of Sega Concaves.
(Viper Night Drivin, Star Wars Trilogy, The Lost World JP, X-Files, Spacejam, Starship Troopers)

I was lucky to purchase these during 2010 and was happy to get the set cause each of these machines are so unique and engineered differently to alot of machines before them, plus the headbox shape which is so more modern than the tired old square backbox. I also picked up a RFM and a SW Episode 1 which fell into my lap with luck.
A friend imported me a excellent GODZILLA, also a 1998 Sega machine as a surprise, and it only cost me 2 grand, which i was stoked about. That was 2010.

2011 holy grail will be to pick up a really nice Indianna Jones widebody, and maybe a Addams Family at the right price. I have saved a few of the best to last.
Any more than 35 machines and my wife might cut my balls off !