Ten Modern Poets
but
check this page
for the full list of greatest poets of all time.
If you want to check just ten modern poets, these are my favorites:
Fernando Pessoa
Paul Valery
Thomas-Stearns Eliot
Rainer Maria Rilke
William-Butler Yeats
Juan-Ramon Jimenez
Eugenio Montale
Octavio Paz
Odysseus Elytis
Seamus Heaney
John Ashbery