I have tons of pokémon voice I like, but I'll try to avoid making stupidly long lists~
Japaneseru desu
"SHAMO, SHAMO, SHAMO, SHA!"
Yeah, Wakasyamo's voice owned on many a level. Also, I'm sad enough to know that it makes certain different calls whenever it uses a different attack. Like Overheat. That would call for a "Sha, m-m-m-m-mooooo, SHA!". And Fire Spin would always be a single "SHAMOOO!". Obviously, I need a girlfriend.
I also really like Runpapa's voice, or more specifically, the one featured in the 6th movie's dancing short. That one had nothing but insanity running through it's glee filled veins. Jumping out of nowhere whilst performing a combination of singing and psychotic Runpa laughter was one of the elements that made that short so damn funny. Totally owned 'The Voice'.
Others include, but ain't limited to~
The ape-like Dogomb
Miracle grow Roselia
The ever-badass Juptile.
Hei Hei!
The ear-splitting scream of Utsubot
Heart warming adorable Bayleaf
Eleboo and it's blubbery goodness.
Sooooooonansu!
Rasberry Habunake
Dub
Snorlax (oh god, this was SO much better than Kabigon's voice)
Psyduck
Lickitung
Kanto!Hitmonlee
Weezing (it's first few episodes anyway, before it changed)
Wobbuffet
Stitchdinja
4Kids Corphish
Gulpin