I was disappointed with the amount of new Pokémon. I personally don't count Mega evolutions as new Pokémon, just as I don't count alternate forms as new Pokémon.
That being sad, there are quite a few designs I like. Aegislash is the one true GOAT of Gen VI (sorry Gogoat) and one of my favorite Pokémon of all time. Cool design, awesome typing and unique (and great) gimmick. That's an absolute winner on all accounts. Even got an awesome name. #Aegislash4pokkenharadapls
I also like Trevenant, Tyrantrum, Pangoro, Malamar and Noivern and think the cover legends have interesting designs. Not my favorites, but not bad either. Funnily enough, many of my favorites from Gen VI seem to have been designed by the same
person. They should get this person back for Gen VII.
Also interestingly enough, I think two of the biggest fan favorites of Gen VI, Greninja and Hawlucha, are absolute stinkers design wise. To be fair though, I don't like any of the starters final evos, I just dislike Greninja the most (yes, i was quite salty when he got confirmed for Smash 4). If I had to make a "Top 10 ugliest Pokémon of all time" Greninja and Hawlucha would definitely make the list. Not saying anyone who likes them has bad taste, just my opinion on these two. Actually, I wonder where all the people went who were like "these Pokémon are so ugly they have to be fake" when Greninja and Hawlucha leaked. I remember I wasn't the only one with that sentiment, but nowadays I see them only being mentioned in a positive light.
Overall, I think it was a good Generation for Pokémon designs though, it's just a shame that the number of overall new Pokémon was so low, especially coming from Black/White.