My list:
graphlog. I use it much more than hg log. (wish it could restrict to branches)
purge. remove all files not in Mercurial. I use this instead of or as a cleaner version of make clean.
Less used, but nice:
- children (lets you say "hg children -r XXX")
- parentrevspec: lets you say stuff like "foo~2 = foo^1^1 = foo^^ = first parent of first parent of foo"
I keep trying to use the history editing tools, but keep running into limitations. I want them to work.
- collapse
- histedit
- I consider rebase a history editing tol as well
By the way, beware: hgk and fetch are "unloved": https://www.mercurial-scm.org/wiki/UnlovedFeatures. But then, SubRepos are, not unloved, but a feature of last resort, and I use subrepos.