Top 5: Starting with most favorite
1. Venusaur, 2. Mawile, 3. Charizard, 4. Ampharos, 5. Mewtwo
Bottom 5: Starting with least favorite
1. Lucario, 2. Blastoise, 3. Kangaskan, 4. Absol, 5. Blazekin
Venusaur's evolution has a very tasteful addition of it's more intricate jungle foliage design. Mawile and Charizard, similarly, feel the same, yet enhanced. The designs seem deliberate and purposeful rather than adding a extra bells and whistles aimlessly. Ampharos, this one is controversial. However, the hair is not a random addition, rather, it distinguishes Ampharos as a bearded Dragon, also tying in the sheep wool ancestry. Lastly, 'New'Two has an interesting horned-crown design, also the elongated and tapered head-tail, suits the intelligent enigmatic personality of Mewtwo.
Generally, for the ones I am not fond of, there seems to be many unnecessary tassels, odd color palettes, over-design, or just plain-old gauche designs in relation to the Kangaskan line.