Otunga's spinebuster is far from great but it is also far from the worst finisher ever.
MVP's original Play of the Day was truely awful. R-Truth's Lie Detector is weak looking, as it JoMo's Starship Pain. Pretty to look at, sure but rarely hit properly and do not seem like they could be any more painful than a normal body slam.
Outside of WWE (and perhaps outside the brief of this thread) Shane Douglas' Belly-to-Belly Suplex was rubbish as a finisher as was Sandman's White Russian Legsweep, mainly because both moves are normal moves with nothing different added to them. And before you say it, what difference was Sandman holding a kendo stick really supposed to accomplish? I was never sure how Luger's Torture Rack was meant to be in anyway painful aside from the uncomfortableness of being rested on someone's shoulders. Jarrett's Stroke was also extremely weak for me and I am not sure why the Miz is using a glorified version of it. Sure, it looks good when someone like Sheamus dives head first into the briefcase but in a normal match, I find it the epitome of unimpressive.
Otunga has become a lot better at delivering it recently and does get a decent crash from the mat, similar to Barrett's overhead slam. To make it a bit different and perhaps more impressive looking and sounding, when he elevates his victim, Otunga could add in a sitdown element similar to the Batista Bomb.