Hrm, I'm not so sure either way personally. I think the US produces more in terms of quantity so it may have more better shows due to that that. Perhaps your point on realism maybe correct though - I hate all of the gritty crime dramas we produce because they are too close to reality for example, so I can't really comment on that since it's a taste-bias. Aside from Psychoville and Miranda I can't think of any noteworthy comedies we've made lately, but neither can I think of any US comedies iv liked - I tend to prefer japanese comedy more these days. I think our fantasy tv shows have been bottom of the barrel terrible (robin hood, atlantis, merlin, dr who ect) while US fantasy has been pretty good imo (GoT ect), US has some good horror shows too (Wynona Earp being the most recent I enjoyed) not so sure on Sci-fi - the only recent US SF show I like is The Expanse, and the only UK one I thought was any good was Black Mirror but I generally think 99% tv/movie SF is terrible anyway.