My most favorite Fluke AC72 Alligator Clip Set, this is now discontinued or reclassified. I have two pairs of them and for low-voltage applications they are great.
http://en-us.fluke.com/products/all-accessories/fluke-ac72.htmlFluke nowadays suggests as replacement Fluke AC175 Alligator Clip Set, this is somewhat improved with additional isolation at the jaws.
From the other hand, Asian copycats they did create one equivalent to AC72 Alligator Clip Set, which this is a totally bad idea.
I would say this is a huge AVOID, because such a system this will eventually destroy the tips of any quality test leads set.