Orianna for utility, karthus for late game dps, kayle for dominating the lane and hopefully roaming, ad assassins for a similar reason.
TF as always stands out for pushing and roaming, anivia will push really well and prevent tower sieges from the enemy team from being too effective (same with lux)
Other than that, ryze for late game like karthus, works better against ad mids, ziggs has seen some use for the global ult.
Keep in mind too that most tops work well mid anyway, your mid really doesn't have to be AP.
(even all ad teams can work, just build tonnes of pen)