1. Gyro and its successors (Haute Horlogerie and amazing complications)
2. Duometer and its successors (Haute finishing and interesting and practical complications - something that can really compete with PP and AL&S at the $40k level)
3. Compressor and its successors - a new, easy and reliable water restistancy system that gave JLC a signature look. It pains me to see how uninspiring the Polaris line is in the wake of the Compressors.
4.Extreme World and its successors - An effective, very COOL shock-absorber system to protect the movement. I feel that this should have been JLC's response to the ROO. The addition of the case-dependent strap change mechanism was also revolutionary and awesome!
5. AmVox 2 and its successors - Perhaps the coolest chronograph series on the planet! When the 7 came out with the strap-change mechanism, it was perfect.
Alas, with the exception of the Reverso Tribute Moon and Tribute Calendar and the Duometer QL and UTT, the rest of the line-up is pretty boring these days (and that hurts, since JLC is my favorite brand).
-Dean