Need suggestions - bonus offers for opening a credit card

I will be freezing my credit very soon due to a possible security breach (gmail notified me that my email account was accessed by someone in China so maybe someone is in the process of stealing my identity now).

Before I freeze it for a few years, I want to apply for an extra credit card for emergencies. I am looking for a great bonus offer for opening one. The last credit card I opened was Southwest Rapid Rewards and I got a roundtrip airfare and a $500 gift card (with card usage) which was great.

Any suggestions? Thank you!