About the whole pixel art/scratch sprite thing...you shouldn't worry too much about that; around here, they're practically the same thing.
Anyways...my favorite one's the eevee. In my opinion, it's the most well-done out of the three - the anatomy is decent, the lineart is relatively clean, and...yeah.
For the others...they're not bad, though maybe you should try to experiment using an outline other than black, like you did on the eevee. Though I'm not saying you shouldn't use the black if you want to use it...just...that maybe they would look better with other colors, as black tends to make things look extremely 2-d. ^_^;;
And if you could, also try to fix the charizard's wings...the way they're sorta disconnected in the middle makes no sense, really... O.o
They're still good tries, though...keep it up with making them. ^^