I use Gif Movie Gear for animation purposes. Does all the positive stuff JG00 says his Animation Shop does PLUS lets you pick a transparency color for the whole animation with one click. I'm guessing a newer version of Animation Shop would probably have that feature. It's not the sort of feature I would think really advanced and hard to implement.
Another thing GMG does that I like is a "blend animation", which puts one file on top of another and automatically works out the frame timings. In most cases, it's useful for putting the moving part of the animation on top of the background, but it's also handy for combining different animations entirely,
like so, without having to piece together the frames one-by-one.
For actual graphic editing, I have Photoshop Elements. Does pretty much everything you would need Photoshop to do, plus many things you don't. I think more people understandably prefer Paint Shop Pro which is a little more slimmed down and more easy to acquire. I got my Photoshop as a gift though and I'm not complaining.
Gif Movie Gear also has a feature that can open up the graphic editor of your choice to edit a frame on the spot. I have it link to Photoshop, of course. It can be tricky though, if you're not careful to stay within the original palette of the frame, then when you save the gif, you may be surprised to find that frame to have suddenly changed to a psychadelic mess of all the wrong colors.
Photoshop Elements can also create animations itself, though through a much clunkier method nowhere near as good as GMG. It has no problem expanding the palette though, naturally reducing to 256 colors if you go over, but not losing much overall image quality. So sometimes I'll switch between working on the same animation in PSE and GMG so the programs can compensate for each others' weaknesses in editing animations.