A Renaissance New York Times Square Hotel (4.67/5)
Walk-in from 7th Avenue, head IMMEDIATELY to the right, where the elevators are. Make eye contact with no one. Take the elevator up to the Lobby Level. Exit left, hug the wall, and there's your glorious restroom. Be mindful that The Renaissance just went through a major reno, and one of the features is dark lighting (oxymoron!) so it may be hard to find this toilet the first time. But trust me, it has saved me from embarrassment more than once, and it's worth keeping in your back pocket. Ahem.
B B&H Photo (3.33/5)
B&H Photo's Superstore is awesomely horrible - tons of great merchandise, tons of customers and one good quality bathroom located on the bottom floor along the back wall. One warning: you are required to check your bag upon entry to the store (free) which is never a problem but is sometimes a hassle. Also note the irregular hours due to the observance of the Sabbath.
C Toasties (Union Square) (3.67/5)
This is an easy bathroom to get in to. You need to get the key which is usually on a counter or in a bucket straight back and to the left near the soup station.
D Chipotle (Park Avenue & 31st street) (5.00/5)
Where to begin... this one of the finest Chipotle restaurants in existence and the bathrooms follow suit in all categories of concern. There is a single unisex bathroom on the main floor but the real treat is located up the stairs on the second floor which is devoted entirely to two private bathrooms - one male, one female. During busy hours there is sure to be a line of some kind but the wait is worth it for the blissful privacy you will experience here.
E Bed Bath and Beyond (4.00/5)
Getting to this toilet could not be easier. When you enter the store one of the first things you see is a sign pointing to the bathroom which is located on the left. There are plenty of stalls as well as baby changing stations and it is cleaned on a regular basis.
F Nurse Bettie (2.67/5)
Nurse Bettie could be good for a late night piss if you're out in the area. The bar is small and you potentially will have to present ID to get in — and once you're in there may be a line due to there being only one private toilet.
G Dunkin Donuts (2nd Ave & 33rd street) (3.33/5)
A rare Dunkin Donuts bathroom! Most Dunkins in the city abstain from providing one. It's a one person unit located on the north end of the store, on the side closest to the wheelchair ramp. It says "customers only" but it doesn't seem to be enforced too well.
H Lord & Taylor (5.00/5)
Check the directory for the floor
I Strand Books (1.00/5)
2nd Floor past kids books
J The Bowery Hotel (4.00/5)
Just stroll past the doormen and you're in.