So much the hardest part of your question lies in trying to select something representative of Ovid that I was tempted to reply 'everything and nothing'.
Ovid was something of a poet's poet, which is to say that his work is generally of a standard high enough for others to aspire to. In his earlier work he is a source — often the only source — for much of the Romans' mythology. Ovid was born into a life of privilege which was brutally taken from him, and his later compositions in exile show a face different and gloomier than that of the man who earlier wrote so light-heartedly, although he seems to have retained sufficient of the kindly nature that he had been known for at Rome to keep his readability at a high level.
My own favourite work is the Fasti. It is written, not in Ovid's more usual hexameters, but in elegiac couplets, pairs of lines which can very often stand on their own. I find the subject matter — the Roman year — fascinating, a kind of mixture of history and mythology. It's a pity that it covers only January to June, but it's 'generally worth reading' and 'worth your time', as your question asks for. The episodes are linked to festival dates and the constellations. I particularly like Fasti IV ll.393 - 620, with its quite long account, pegged to the Cereris Ludi or Ludi Ceriales, (April 12-19) of the rape of Persephone and an explanation for the gloom of the winter months and the Earth's resurgence when she returns to her mother Ceres at the start of spring.
Read and enjoy!
