Credit card. There are a few reasons I prefer it to my debit card:
1. If the card gets stolen, you are much more likely to get your money back with a credit card than a debit card. Credit cards fall under more federal regulations than debit cards do. You are essentially at the mercy of your bank's policies whenever an unapproved charge is made against a debit card.
2. Using a credit cards improves your credit score. In particular, paying your credit card bill does.
3. You don't have to actually have the money in your checking account. It can be in your savings account instead, earning you interest. 😛
I use my credit card most of the time... But only if I know I have the money in my chequing account already. If I don't have enough money in my chequing to buy what I want then I wait. (I also usually don't let my credit card get more than $100 on it. I normally pay it off each payday.)
The main reason I use my credit card is because I get bonus points on certain goods that I can save up to turn into deposits into my savings account or discounts if I'm travelling. Plus the card I have gives some nice benefits if I use it to book trips. (Things like insurance and whatnot.)
I use credit card for online shopping, and whenever there is an emergency (like I don't have cash/ debit card).
Debit cards for me would be when I go shopping at the mall. But usually when I go out, I use cash (just for me not to overspend).
I have both, but normally use my debit card when it is more convenient than cash. I have a rewards credit card so I do try to use it for small purchases to rack up points. Also it is what I primarily use when I travel.