I actually really like Diggersby's cry! I remember evolving my Bunnelby and seeing Diggersby for the first time. Shock! And then the icing on the cake - that burping cry. So incredibly fitting! I was in hysterics seeing and hearing Diggersby for the first time. My first thought was some kind of overweight truck driver with a beer belly. It's strangely adorable in a way. Actually, thinking about it, I'm reminded of that truck driver/construction worker/whatever he is guy from Futurama. I guess I like the cry because it's so memorable and full of character. Probably a similar reason why I like Kricketune's cry so much.
Phantump's cry was also mentioned and is one of my favorites. Every time one pops up, I impulsively repeat it back out loud, haha! :P "oooooooooooo!" I guess Heliolisk's cry gets a similar reaction from me in that I repeat it often (though not as much as I copy Phantump's).