Travel credit card recommendation

Which travel credit card makes the most sense for me

I fly domestically about 4-6 times a year and internationally once a year.

My go to airline is united, as I live in one of their hubs. I don’t really care about lounges, I do have an Amex gold with a lot of points on there. But just want to know which card makes the most sense for a solo traveler flying united often.

Thanks