I think porygon, shellder, spiritomb, gastly, among others are cute.
Well... glad you asked.
I recently put together a cute team XD
It contains; Pachirisu, Butterfree, Flareon, Azumarill, Glaceon, Lopunny.
They are my top six.
The notched-ear Pichu is soo cute.
OMG YES, I love the notched-ear Pichu... I want one :(
Any and all Pichu, and Cyndaquil.
Maggyo is cute for me too. :P
I don't mind the occasional cute team member in my games.
I would have to say Jolteon, Minun, Buizel, Hitomoshi and Mijumaru are cute.
But the best: Erufuun. Cutest ever. Absolutely. (In my opinion.)
I really like Pikachu especially when he wears Ash's hat.
I like Mijumaru as well, just seems to get cuter with every episode.
hmm most of the gen 5 pokemon are cute, but especially Kumashun and the Hitomoshi line.
Oh yeah, almost forgot, Castform and chikorita are dang cute <3