If you are a prime member (or family prime member), Amazon currently offers $100 AGC sign up bonus for Amazon Store Card & Prime Rewards Visa Signature Card.
The usually amount is $60. I just applied for both (one credit pull for both) and got $200 GC instantly.
You can apply for other people (not only prime account holder) and also get the bonus.
Wife (or wives), kids, parents, grandparent, cousin, etc.
Rack up the GC for BF
Amazon Store Card:
Amazon Prime Rewards Visa Signature Card