There are lots of shows considered excellent that are not my cup of tea. There are lots of shows I consider excellent that other people don't like.

Thinking about what you like and don't like in other shows can help to find new shows you like. Obviously, I mean looking beyond the genre, as that's generally obvious. Looking at whether it is character driven or story driven. Whether it's an ensemble or has a central character. What themes it deals with etc. Then you can find similar in that genre that are highly regarded and start to branch out to find similar in other genres.

What shows do you like? My tops are West-Wing, buffy, scrubs, line of duty, Rome and the wire. Also loved sopranos, lost, game of thrones, battlestar Galactica and firetly. I definitely skew towards sci fi and fantasy but it's the ensemble character shows I live the most.