The one that's stuck over the years is "Captain", because out of my social circle, I was the one who always made the plans to get together and do stuff.
Other ones stem from my name "Joseph" (much like GamerJM), so "Joe", "Seth" and indeed "Broseph" are used quite regularly.
I also have a habit of giving people I know nicknames too, which confuses the hell out of people when they look through my contacts. I have a "Crazy Pete", a "Red Mike", "Sarge", "Admiral", "Beardy The Mullet", "Fat Daz/Big D" etc.