Others mention the super-fast branching. One person mentioned partial add/commits. Someone mentioned the size difference (it is HUGE... your checkout of one SVN revision in a large repository will be six times as huge as your entire git repo and checked out files!). There is history revision (split a commit, squash some commits together, reorder them, separate them into different branches, deploy what you want! it's like editing a document!). The user interface is helpful and informative if you understand git lingo and version control theory; for example, if you misspell a command, git intelligently suggests commands that are similar to what you meant. On these things alone it blows SVN out of the water.

But to pull a page from Linus's playbook, since no one mentioned it: git fsck. No other SCM I am aware of can fix itself in the event of a small corruption. I have on rare occasion had to deal with these corruptions on network shares, and a "git fsck" brought me back to life in a jiffy. This is really useful for recovering work on your unshared local branches.