The worst. Very difficult to use. You must find an approved restaurant listed on their website first, purchase the gift certificate, print out the certificate and then bring it to the restaurant. Every restaurant requires you to spend a certain amount of money to use the gift certificate. Usually, the certificate saves you half. For instance, the gift certificate may be for $25, but you have to spend $50 at the restaurant to use it.
I have received two $100 Restaurant.com gift cards as gifts (I'm sure it's because no one wants to deal with them). I have used $30 on one of them 4 years ago and will likely not bother using it ever again, it was such a pain.
I have been trying to contact customer service for days now to find out which one of my gift cards is the unused one so I can give it away as a gift, but there is no way to look up that information on the website. I did receive an email in response to my inquiry, but it was automated and did not answer my question.
Thankfully, I've never used any of my own money for these useless gift cards. Just don't bother wasting your time on these.