The one place I can think of is
Caliente Cab Company
in the village.

If you want more recommendations, you may want to try
www.chowhound.com forums.

Actually , just went there and did a search, and found these 2 posts:

In Reply To: Re(4): Best Margarita?
Posted by Kitz on September 09, 1999 at 18:29:05

Message:
by far, and we've had them all over the world, the best margaritas come right out of "tortilla flats' on the corner of washington st and w. 12th in nyc. first, they have herradurra tequila, the top of the best of the best tequilas, and the t.f. margaritas never ever separate!!!!! we hate when two minutes after you're served a frozen 'rita, that the head separates from the base... hate it. they have the best.


and:

In Reply To: Re(5): Best Margarita?
Posted by lydia on October 15, 1999 at 14:40:20

Message:
Try El Teddy's on West Broadway, just north of Chambers Street. Unique mexican food twist, excellent variety of tequilas and "extras" can be combined to create your own delicious margarita.

Edited to add:

If you decide to go to El teddys, invite me since its a couple of blocks from my office.

[This message has been edited by ljp99 (edited 08-01-2002).]

[This message has been edited by ljp99 (edited 08-01-2002).]