I will recommend you Samsung Galaxy S9 Plus. It comes with a large 6.2-inch Super AMOLED display which outputs a screen resolution of 1,440 x 2,960 pixels. Under the hood is a Samsung Exynos 9 Octa 9810 chipset assisted by 6GB RAM which gives the best performance in the class.
A dual camera setup (12MP + 12MP) at the back captures superb quality images and videos. It supports 4K video recording and can record at a speed of 30 frames per second. An 8MP selfie camera also captures sharp quality images. The primary camera also comes with a variable aperture to capture better low light images. The smartphone is packed with a 3,500mAh Li-ion battery which helps keep it running for around 25 hours. The Samsung Galaxy S9 Plus is one of the best smartphones in this price segment.
You can also check the complete comparison here: Xiaomi Black Shark vs Samsung Galaxy S9 Plus