Chip and PIN has some serious security flaws (there are ways to produce a magstripe card from skimming the chip and PIN data), but it does fix some security problems by changing the card processing flow to require that the cardholder be at the card terminal to enter their PIN.
The signature system used in the US is a massive joke, really. (And, in many sit-down restaurants, your card often ends up being taken out of sight to be run through the credit card terminal, then they come back with the receipt to sign.)
Debit cards in the US are magstripe-and-PIN, for what it's worth.
Also, the workflow for self-scan POS usage of debit cards here in the US... if you scan it, and it's detected as a debit card, generally the terminal will present options related to processing it as a debit card, but you can cancel out of that, and then select to process it as a credit card. IIRC, as a debit card, your bank (and sometimes that gets passed onto you) pays the transaction fee, and it's a magstripe-and-PIN transaction (the PIN is sent to the bank to verify, rather than to the card), and you can choose to withdraw additional funds above the purchase amount. As a credit card, the merchant pays the transaction fee, it's magstripe-and-signature, and you can't withdraw additional funds.
