(cue DELELELELEWHOOOOOOOP)
Can't say I'm fond of Raichu's or Dugtrio's X/Y cries.
I agree with you, they don't sound as awesome as they used to. I also hated Karrablast's cry in X/Y.
As for my fave cry in general, it probably has to be Sylveon's. I love how it shows the epitome of cute. For most memorable, it's Kricketune's signature DELELELELEWHOOOOOOOP. It'll never get out of my head.