Nokia 6 (or Nokia 6.1)
Believe it or not, Nokia actually makes some pretty excellent Android smartphones these days. With each release, the phones get better too.
The Nokia 6 is perfect for those on a tight budget. You get a brilliant and surprisingly good 5.5-inch Full 1080p HD display, a fingerprint scanner on the front of the phone, and dual stereo speakers. Unlike most cheap phones, Nokia didn't skimp out on the hardware materials either. The frame is an extremely strong aerospace-grade aluminum.
As for specs, you get a Snapdragon 430 processor with 3GB of RAM, 32GB of storage, a microSD slot and a pretty capable 16 Megapixel camera on the back. There's also an 8MP front-facing camera, Dolby audio support, USB Type-C, a headphone jack, and nearly stock Android.
The old Nokia days are long gone, but this is a pretty great Android phone for the price.
Or, get the all-new Nokia 6.1 (2018) model with an even bigger 6.1-inch display, a more powerful Snapdragon 635 processor, and tons of improvements for around $275 at Amazon. The Nokia 6 2018 model was released in April of this year. It's sold out already and costs more than last years model, but they're both great cheap Android phones.