I know the initial thread was asking which microchip but it seems to be drifting into which company do you pay to keep your data connected to your pup.
While researching chips, I came upon the Companion Animal Recovery (AKC CAR). It is a non-profit organization and pet recovery experts for 15 years.
If your pet has a microchip, the number of that microchip must be directly linked to you. This is done by enrolling it in a recovery service, like AKC CAR. AKC CAR enrolls any brand of microchip and provides you with peace of mind that your pet is protected for its lifetime with NO ANNUAL FEES. Our toll free number assures you that no matter what time of day, or where you are, or what the weather is like where you live, AKC CAR is available 24/7 to help your pet return home to you.
The cost for the lifetime of the pup is $17.50 no matter who's chip you use.
So for those of you (like me) that have your dog chipped but not on a database, this might be a good one!