Honestly my favorites are
1. Razer ripsaw

Product Features
Compatible with your existing game system
Plug and play with PC, Razer Forge TV, Xbox One, Xbox 360, PS4, PS3 and Wii U

Superb quality
Easily broadcasts to popular streaming platforms in crisp clear 1080p at up to 60 frames per second.

Stream over USB 3.0
Captures your game footage as uncompressed raw data and streams it on with near-to-zero latency over USB 3.0. No screen tearing, no artifacts, just ultra-smooth streaming.

Professional-grade second audio mix-in
Plug in an aux-in music source or mic-in capable microphone to the Razer Ripsaws second audio mix-in channel to conveniently layer your stream with commentary, or the right companion music track.

Compatible with popular streaming software
Designed to work with industry leaders like Open Broadcaster Software (OBS) and XSplit, giving you access to a wide range of powerful tools to produce captivating content.

PC System Requirements
Windows 10/8.1/7; USB 3.0 port; Intel Core i5-4440 3.10GHz or above; NVIDIA GeForce GTX 660 and above; 4GB RAM or above.

2. Elgato

Product Features
Functions: Video Game Capturing

Maximum Resolution: 1920 x 1080

Platform Supported: Mac, PC

Host Interface: USB 2.0

HDMI: Yes

Form Factor: External

Height: 0.7"

Width: 4.4"

Depth: 3"

Weight (Approximate): 3.74 oz

They both are good in there own right my favorite is the razer ripsaw though