I started my exploration of the Korean TV series with "Tunnel", an excellent series, then I watched "Signal", **the best TV series I've ever seen in my whole life**. I've just finished watching seasons 1 and 2 of "Cheo Yong", and even though this series is good, it's still far from the standards established in "Signal" and "Tunnel". Many good moments, some awful ones, and some excruciating (vain attempts at humour with silly music), but yet, all in all, the good moments mark the point. However, I will watch again "Tunnel", and especially "Signal", but "Cheo Yong" will not be on my list of watch-again series.