Lula's is probably the reigning favorite vegan ice cream shop in NYC, and has been for as long as I can remember. They recently closed for a while, allegedly due to some dispute between the owners, but they are open now, and rejoicing is abundant.
Their chocolate ice cream is good, but honestly no better than a number of others we've reviewed. What's nice is that they are an actual shop, where everything is vegan. So you can get a vegan egg cream, a vegan milkshake, a vegan float, a vegan sundae, etc.
To give you an idea of the quality, the first time I went there (many years ago), I didn't realize it was vegan and ordered a chocolate egg cream. I thought, "This is pretty good, but it's nothing special. Ray's makes a way better egg cream just down the block. Why does everyone make such a big deal about this place?" But notice that (1) I thought it was pretty good and (2) I did not realize it was vegan.
Bottom Line: There is no particularly compelling reason to go to Lula's if you're not vegan, but if you are, and you're craving a real ice cream parlor experience, then Lula's is a great -- and as far as I'm aware unique -- option.