The LG G6 is over a year old at this point, but if software updates aren't a major concern for you, it's still a pretty good phone. The 2017 flagship has now dropped to just $250 on B&H — that's $350 lower than the original MSRP, and $150 less than the current Best Buy price.
The G6 has a Snapdragon 821 processor, 32GB of internal storage with microSD expansion, a 5.7-inch 2880 x 1440 IPS LCD screen, and 4GB RAM. The rear camera is 13MP, with an aperture of f/1.8. The front-facing camera is 5MP, with an aperture of f/2.2. This specific model (H870) is the international European version, but it will work just fine on AT&T and T-Mobile in the US.
The phone shipped with Android 7.0 Nougat, but it was updated to 8.0 Oreo a few months ago. There's also an official port of LineageOS 14.1 (based on Android 7.1), if custom ROMs are your thing. You can buy the LG G6 from the source link below.