1. Gym membership. If I wanna run, I'll run outside. If I want to do cardio indoors, I'll jumprope. Boxing bags, gloves, and handwraps are also inexpensive. Treadmills, bikes, etc. are a joke. You can easily get stronger for free, without weights or machines. Old school boxers didn't need that junk. Do pushups, sit-ups, bodyweight training, ghetto workouts, Spartacus training, etc.
2. Expensive data plan for mobile phones- if you don't need it for work, it's just an expensive Facebook machine. Convenience is boring and doesn't justify the cost.
3. Sports fanaticism/cable - I like sports, but it's no big deal to me if I miss every live game. Cable is expensive, yet everyone seems to justify the cost by "sports!"
4. Macbooks- you gotta be kidding me with this, what a hype machine in college campuses. Go to a Uni lecture, and you'd see 90% Mac users. What do most people in Uni use it for? MS Office, photobooth, facetime, and internet!
5. Alcohol. I don't get it. It's disgusting and expensive.
6. Expensive restaurants/food- it may taste good, but marginal benefit relative to cost. I tried Molinari Delicatessen and gelato in North Beach, SF. What a waste of money.
7. Coffee- a dumb money pit, and probably no cognitive benefits for your workday.
8. Asian fetish/yellow fever- bunch of weirdos.
9. Traveling- I've been to Europe once, no big deal. The truth is, I can't stand packing.