I've been going to Chrysler Cleaners for 3 years and they are amazing! I have to pretty much alter all of my clothes to fit properly and they never disappoint. I've had jackets, coats, jeans and dress all taken in. The prices are also reasonable. I'm 5'2 so all my pants need to hemmed and it's a mere $10.
It's also a revolving door away from Grand Central making it easy for me to drop off clothes before work and pick them up on my way home.
I strongly recommend them. Unlike girlinthecity I've never had a bad experience with them. The owner is also very sweet.
Pros: excellent at alterations!, close to the subway