Cato's famous phrase, "Ceterum censeo Carthaginem esse delendam", is feared for its grammar, but it is quite expressive and not really that hard. It is a combination of two constructions: ACI, Accusativus cum infinitivo, which also exists in English, sort of: I see he swims or I see him swimming (in Latin it would be "I see him to swim") = I see that he swims. The other thing is the gerundive, which expresses an obligation. Sounds complicated, but it really isn't - same thing as English "This is to be done" meaning "This ought to be done".
Now, in Latin, the ACI construction can be done with many verbs, not only "to see" ("I see him swimming") but also with "censeo", or "I opine, think" ("I opine him swimming" - I think he swims.) Next, throw in a cool "Ceterum" = by the way, and combine this with the obligation of the gerundive, and we get:
Ceterum censeo Carthaginem esse delendam =
"By the way, I think that Carthago is to be eliminated."