Recently I was doing some clean up (deleting) my emacs buffers, and I was a kind of boring task having to open each buffer and kill it (one at a time).
And I found that you can do it quickly with Helm.
If you run M-x
helm-mini (I have it mapped to C-2), you can see a list of open buffers, and by scrolling through the list and selecting the ones you want to delete with C-Space.
When you have them all selected, just press M-S-d / M-D, and all selected buffers will be deleted and Helm closes.