The git GUI in Intellij and related products is really quite good. The diff view that shows three adjacent panes for conflict resolution (|theirs ->|merge|<-yours|) is so much better than the normal conflict resolution flow (not least because you still get the normal code highlighting in it), and separate checkboxes for each changed section of the diff makes it so easy to chunk large changes into logical commits. I wish they offered it as a standalone product.
