Dang, going off strong with your items AND the Nike bag. Strong arguments, I can't really fight you on that... For me I think I would have to run with a:

1.) Laptop, because the utility is key and can provide many different tools in one package
2.) Portable speaker, music is an "anytime" type of thing, crazy to go without it
3.) Phone (Not sure if this counts or not as I have pockets) but either way, I need my phone to be able to take pics and do simple/fast things.
4)Metal water bottle, gotta stay hydrated no matter what you're doing.
5.) A small toolset, never know when you'll need it, and I'm a tinkerer.