The amateur radio community (ham radio) tends to spread misinformation about 1:1 BALUN, also known as Common Mode Choke, RF Line Isolator, etc. Although they are all the same device comprised of ferrite material core(s) and mostly 50 Ohms coaxial cable, the design, material, size, etc plays a major role in the final performance.
What is a good 1:1 BALUN? This is the wrong question. Instead, we need to ask what BALUN performs the best for certain applications?