As far as a series,I'm another who really likes the Musclecars USA series,it's what brought me into the JL fold.Second would be the Camaro's series.
As for a set,I really like the Head to Head set with the white 68 and green 71 442's,along with the JL starting line christmas tree.Second would be the set with the 69 red,white & blue AMC s/c rambler and the red AMC AMX.
I have too many sets that I like.
The GTO series, the 50 car covette series and the Head to Head set with the 69 red,white & blue AMC s/c rambler and the red AMC AMX. Then there is the Mustang Madness set, and the Mopar Madness.
Hmmmmm.....brutal decision. Frightning Lightnings are way up there, as well as early Hollywood on Wheels and the Tom Daniels cars. The Hot Rod cars were way cool, but the original 10 car Mustang set is what really got me to look at Johnny Lightning in the first place.