So far the episodes have been pretty good but Episode 7 about the Oculus Rift was fantastic - highly recommend it! (For reference i believe South Park peaked in the first half of series 11 and has never returned to this high point!)
Season 16 was pretty good, especially "Cartman finds love". That oculus rift episode was brilliant. "The hooker stabbed me!!!" hahaha
Series 18 has really impressed me so far - I think a lot of effort has gone into it this time. For the record, Randy is my favourite character. So many awesome one liners!