Hey, pickles! I've lived in Midtown since 1987.
I'm not a lapsang fan myself but I'm told that Seven Cups's lapsangs (they carry souchong and bohea) are very good--I gave samples to an English colleague and he liked them both. Really wonderful Assams are available through Assam Tea Co.--the owner used to market his own teas as "single malts." I stick with them because they seem to fulfill my needs but I'm always open to new offerings.
The only vendor I liked in Manhattan closed; it was the Ito En shop on the UES and they were the only brick-and-mortar source I knew of for imperial grade white Silver Tips from Darjeeling (their other offerings just seemed overpriced and mediocre).
I did stop in at the Tea Gallery once but it was way out of my budget and I wasn't convinced they could provide me with anything that was available elsewhere (for less).
What are you drinking lately?