I actually, in all seriousness, completely disagree that a synth is the worst "first" pedal. Synths are fun. I could easily see it being someone's only pedal, and therefore why not the first?
I stick by my answers from earlier. The worst pedal would be a line selector or bypass looper, since you wouldn't have any other pedals. The second worst pedal would be something you don't understand. The third worst would probably be something too subtle to be worth your time.
+1
A Bass Synth Wah was one of my first pedals.