Had to go with "And the Children Shall Lead". First, it has kids in it, which is pretty much always going to get you into trouble right away (the occasional Jake Sisko DS9 episode being maybe the only exception to this rule). Second, the lead guest star is a criminal defense attorney wearing feathers. Finally, "Hail, hail, fire and snow..." Need I say more?
"The Alternative Factor" is just, gibberish, but that's not enough to win. And I tend to let "The Omega Glory" off the hook for featuring the halfway decent composite shot of both the Enterprise and Exeter in orbit, which actually looks like they might be two different ships, rather than two copies of the exact same shot pasted together. (See "The Ultimate Computer".)