I have Punchy on my island now and he's super cute! I think Lucky is cute too though, so this is a really tough decision... do you have any themes going on for your island that can help you decide?
I voted for Punchy only because I've only ever seen him. I've never seen Lucky on an island before so I have no experience with him but he's also very cute!
But then again, I've never felt attached to Lucky whatsoever. He creeps me out too much, and not in a fun way like my arch-nemesis Bubbles, or in a nostalgic way like Tabby, or in an -OMG- way like Hopkins (the first time you see the back of his head and realize what's hiding there in plain sight).
Punchy has historically always been one of my favorite AC villagers, dating back to my second town in AC (same applies to Bob). I've had him at some point in every game since then, not by searching specifically for him but just by pure luck (like Rosie).
Still, I can appreciate Lucky and his design! It's certainly unique!
Oh this one is really hard... I love both but if it were me, I would have to go with Punchy. Unless I had a scary/haunted area, then maybe Lucky. It really depends, both are too cute.
Do you have a theme in mind? Maybe one fits the theme more than the other!
A friend of mine really likes Lucky so it's helped him grow on me, but I used to not like him at all. Punchy has always been one of my top 2 favorite villagers so I'd choose him without a doubt!
Editing to explain my reasoning a bit more: Yes, Lucky is unique for being a mummy dog and it may seem like Punchy is just another one of the 30 cats. But Punchy is one of only 3 lazy cats and out of those, he's the only one who has whiskers and he also has an adorable :3 mouth and sleepy eyes that all work together to make him look so sweet and easygoing and absolutely perfect for the lazy personality. I've just always found him to be way too adorable no matter how common cats may be!