Most gifs these days is via custom tools that will basically rip the frames and assemble the gif. Just give it a start and stop time, a video file, and grab a latte...
Maximum quality is usually via
Video editor:
VirtualDub
MKVToolNix
(cut a scene and convert to uncompressed video)
GIF editor (they are still around):
Jasc Animation Shop
Ulead Gif Animator
(open uncompressed video and convert to GIF)
And there are a ton of noob-friendly tools that combine the two.