In my opinion, you have two premier choices in Soraka or Taric. Soraka is probably my favorite if your Urgot can land the all important skillshots. There are not too many folks who can stay in lane long against a never-ending barrage of homing Urgot Qs, and free MR is never a bad thing, especially not on the tanktastic Urgot. Taric is a great second choice since the stun helps your Urgot land the E into Taric's fabulous burst into the Q spam. On top of that, considering the way Urgot builds and his passive, the armor from Shatter REALLY beefs Urgot out further vs AD damage.