ADC Ahri. You get a CC, true damage and mobility.
Manamune & Seraph Syndra, but I saw this in low elo like Silver. It worked.
Full AP Blitzcrank
Bruiser Diana (Hybrid AP & AD)
ADC Malzahar. New malzahar makes this quite viable I would say.
AP Maokai. I used to do this for fun. I did a really decent amount of damage.
AP Nami top/mid. If you can land bubbles, you will own. Guaranteed. Start E for early lane dominance.
Bruiser Elise. Strange build. Not super strong but somewhat strong enough to solo squishies. Fun to use if you know your way with elise.
OR
You could just make a rune page with 20 MPEN and use that on any AP champ. It's fun to shred people with.