I have to say I am partial to Ngewvu and Mnyamawamtuka despite difficulties for some people to pronounce and spell. I second mike that Brontomerus stands out, but I find -oposeidon a bit cumbersome no offense. Lythronax and Polacanthus also seem appealing to me.
The worst for me have to be a tossup of unbelievably shortened or flowless names like Yi, Zby, Thanos, or Iguanocolossus or Thanatotheristes. Intentions were good but not good enough.