I'm NOT a spriter, but I decided to try revamps. I have a lot that I want done for my hack so I picked up the mouse and tried.

How are they? I've never done revamps before, my only experience with Pokemon sprites is recolouring and a tiny bit of fusions. So don't be too harsh on me :3
Pretty good job with those. I don't think you need to keep much of the dithering from the original since you have 16 colors to work with, but all of it is in less noticeable areas for the most part. I would smooth out the highlight over Blastoise's eye and possible the arm, too. They're a bit jagged. Also, on that same arm the nail furthest to the right has a lighter outline than the left side when it should be the other way around to be consistent with the direction of the lighting.
I made this badge for a Pokemon League thing where I'm the Ice type gym leader (On different forums).
It's the Arctic Badge.

Thoughts?
Well, ignoring the fact that snow flakes have 6 arms instead of four, it's not bad. A little bit simple design-wise, but the colors are good, the reflection effect with the lighter area is good. I don't really like how the outlines on the points are one pixel off. It seems a bit halfway to me. I'd either make the whole thing straight or I'd make the difference greater and go with a more elaborate outline.
i did major editing on my ghost-dude, seeing that it is my worst at the time(other than the sand- thing, but i dont see a way of that being fixed anytime soon)
It's an improvement, but I think you could get more out of this. The eyes are a nice design element. Having the one cut off makes it look like they're flat on the 'sheet' and the cut off one is wrapping around the edge. That's fine, but I'd be nice to see a little more of it since over half is missing.
Right now it looks as though we're staring at it at about eye level. Its eyes are equal in height. The shading is mostly of a left/right variety. All this makes it look a bit static, a bit like it's a flat picture. On the official sprites you'll notice that a lot of the time the eyes are not equal in height (or size for that matter) and usually aren't so close to the top of the head, or the portion of the body we can think of as the head. When the eyes are the focus of your sprites (because let's face it, there's not much else to look at here) they need to do more than sit there.
The shading is getting there. Cloth is hard to make look realistic. Right now you shading is smooth and that would be perfect for something round, but with folds and ripples you get weird shapes. I'd look more at the ghost pokemon sprites Dots pointed out. For a real world exercise in shading you can also try holding up something like a shirt to a lamp to see how the light plays with it. That's to get the 'feel' of shading. Spriting it will be trial and error.