I love both PAGG and CAX equally, for different reasons.
I love PAGG because it's exclusively pins and I'm usually seriously jonesing to play lots of other pins, buy parts and pieces that I missed on a recent order, and it's such a laid back show that it's damn near a requirement to go. Plus, the car show on Sunday is awesome(I'm a car guy who grew up on British sports cars, even though all I have now are Mustangs)!
CAX takes me back even more so to my childhood in arcades playing ALL of the video games, plus it usually has about 50% of the diversity of collection that PAGG typically has, and almost as many pins. It's such a kick to walk in there and hear the sounds of days gone by. This year I plan to take a few audio recordings of the sound in there. Further, it melds two sides of the classic arcade hobby and it's nice to meet the big time vid guys that are always every bit as awesome as the pin guys.
Both are great shows that are must-go's at least once in your life!