I've been waiting for someone to mention magit. It is the only UI I know of that is more than just a git shell. Real thought went into it and it shows. It is faster and more convenient than the command line, which says a lot.
It's still not as fast as vim-fugitive for example. I know magit does more in nicer ways but the delay when staging, for example, is noticeable and can be annoying over time.
