Git commands sufficient for 99.9% of the time:
git status
git add -A
git branch
git checkout [-b]
git rebase [-i] master // interactive rebase is amazing
git reset HEAD [file] // when I accidentally add something
git reset HEAD^1 // for when you accidentally commit on master
git log
git diff [--cached]
git commit // try and avoid '-m' and single-line commits for most stuff
git commit --amend --no-edit // quick 'fixup'
git pull
git remote -v
git stash
Never git merge (except through git pull).
If you have a messy merge/rebase conflict, prefer rebranching off the branch you are merging into and copying over your changes manually.