Ugh, two shows I really never liked. But of the two I absolutely could not stand Green Acres, I remember in sixth grade in the week leading up to Christmas my math teacher was sick so we basically just watched old shitty dubbed episodes of this show on VHS for the hour we were supposed to be doing match. Never in my life would I have thought that I'd actually PREFER doing mathematics to watching television, but Green Acres brought that out in me.
Dennis the Menace...meh. Can't say I ever really saw much of the original show, but I really liked the modern movie when I was a kid, so it's getting my vote here. That and I really dislike Green Acres.