I like spike as a character and i think he is charming, funny, likable. But his episodes are 50/50. In most episodes i found him quite loyal to twlight including the ending.
Spike eps i like
Gaulet of fire, times they are a changling, molt down, equestria games, sercut of my excuses,dungons and discords and inspiration manifestation.
Spike eps im ok/meh on
Power ponies, just for side kicks, spike at your service,
Spike eps i hate
Dragon quest, princess spike, owl ends well