Really love Hikari's decision above.... Oshawott and all its evolutions, especially Dewott!!
for me (even if everyone disagrees - I'll still find it cute) Watchog!! especially that hypnotizing view from its eyes, its fur markings, those weasel-like ears (since I play with my mom's husband's ferret a lot), the white tuft-like on the tip of it's tail, and the Meerkat-like pose it makes when standing up, in the BW episode 115 [The Pokemon Harbor Patrol] I just loved its voice, sounded really cute - I had to use it as my tone for received text messages (at least its Japanese voice, hope its American voice is even cuter though) (can't thnk of any more reasons why for now)....... I also find Patrat cute as well primarily for the same reasons
also I love Mienfoo's shiny design - that blue fur.
Mienfoo and Mienshao's markings on it's head... every time I play with my (actually my mom's husband) ferret, I can imagine myself playing with a Mienfoo or Mienshao. That fur tickles the back of my neck, or when it brushes up near my ears, when I try to catch it, when she runs around.... that cuteness will never end