I have plenty of straight guy friends but none that I claim as a 'best friend'...
Straight guys kind of fascinate / weird me out at the same time. The legitimately just have such a different dynamic than how I interact with my girl friends or my gay friends. It's like we exist on different mental wavelengths, not to imply that one of us is more intelligent than the other but I just think and act so differently than my straight friends do... IDK