@Axel-Ridge
For a few trips a year, the United Explorer ($150 fee) is a gamble. You'd need to check four bags just to break even. The Chase Sapphire Preferred card ($95) is a good choice. It offers 3x points on dining, 2x on travel, and allows point transfers to United.

To justify the annual fee for a United card, you typically need to fly three times a year with a checked bag to save enough on baggage costs.