I used to have to replace my dogs tags every year - they were the inexpensive metal ones, and the engraving would wear off just from rubbing on their dog license, even after a month they started looking bad and sometimes unreadable... what a waste of money! But not any more since I found Wooftags. Last year I bought two tags from Wooftags, a plastic heart tag and one of their "guaranteed for the life of your pet" staineless steel collar tags. These are like the rolls royce of tags in their quality, except they are just $10 including shipping and tax! PLUS how great is it that they donate all their profits to rescues. =)

Pros: durability, cost, rescue-friendly

Cons: none