My least favorite modern Phil tic is when something happens to him in a game which surprises or annoys him, and instead of reacting he keeps staring at the screen in the hopes it will become a viral moment. His desperation to make it a viral moment, though, means he does it probably 10 times per stream.
I get the joke, being so flabbergasted you're speechless and all. But that particular bit has two timings that can work- stare for a moment and then react, or stare-stare-stare til how long you've been staring becomes the joke. Phil often tries to go for the latter, but because he is autistic he hits the absolute perfect middle timing every time. We watch him stare, think he'll react, but he does not. So we keep watching him stare, anticipating his explosive reaction, his punchline- but before the overly long stare becomes humorous in and of itself, he reacts, and usually it's just to say "come on".
He never thinks of a joke, he never uses this time to pan his degenerating mind for comedy gold, he just stares because he probably saw it in a movie or TV once, or in an epic style viral clip he saw. Because he is socially retarded/autistic his timing is precisely off enough to indicate that this man has special needs to any outside viewer, and since he does it so often it wastes time in what is already a mind-numbingly boring stream since he is constantly reading chat and scanning for donations.
It's just so fucking exceptional.