There is a place called USO (don't know what that acronym means but I'm calling it Moocher's Paradise) somewhere near Times Square where military peeps can go for discounted Broadway/off-Broadway tickets. We went to see what they had to offer and low and behold--FREE Blue Man Group tickets! [Disclaimer: This show is disturbing and hilarious and mostly weird. But enjoyable nonetheless because we didn't have to pay a cent for our $90 seats. Basically what I'm saying is, don't go to this unless it's free.] On top of that, there is a whole lounge area with piano, Foosball, leather couches, computers, and enough free soda and Girl Scout cookies to feed an army (no pun intended).
2. Disregard all "suggested donations."
If you don't mind the awkwardness of the cashier at the Metropolitan Museum of Art cursing you in her head as you hand her a few scrappy dollar bills for a group of 4, when the "suggested donation" is $25 per person, you will save yourselves a collective $96 that can otherwise be spent on dinner...for, like, a week....unless you just eat Girl Scout cookies at the aforementioned USO...
3. Sit on the cold pavement in the wee hours of the morning.
For the real nitty gritty taste of NYC, one must spend at least a few hours bumming like a hobo on the ground, inhaling the exhaust of passing delivery trucks, inches away from gutter trash, un-showered body and un-brushed teeth. All in the hopes of getting *extraordinarily* discounted Broadway tickets. After 3 hours of numb toes, morning breath, and trivia games to pass the time, we got $40 tickets to "Once" (reg. price: $97-$252). If that wasn't good enough news, turns out we got our own private box seats!