I also find that it varies by country - Greek hummus is much milder than Middle Eastern forms.

I personally love the hummus at the chandalier restaurant in dubai marina..nice, creamy, and has a few pine nuts on top.

their falafels are the best in dubai too!

Cooks Illustrated/America's Test Kitchen had a hummus recipe a few months ago (looked it up: May - June '08 issue). The trick to smoothness is to make an emulsion like mayonnaise. When you're doing the food processor bit, chop up the solid ingredients first, then add the non-oil liquids (lemon juice, chickpea broth, etc.) and finally, in a slow stream, the opils (olive oil, tahini).

Topping hummus with sumac is also good.

Trader Joe's here in the states has nice selection in case you haven't heard.
I like the three-layered myself.

To the original poster, I find it strange that you went to a Persian restaurant and had hummous. Hummous is not an Persian appetizer. If you were to go to Iran or even to an Iranian person's home for dinner, typically hummous would not be served.

Having said that, I make it at home ---usually skimping on the tahini and the garlic, and adding lots of lemon juice. I find all these new hummous flavors to be really odd, but as long as you think of them as hummous in the abstract sense, they are okay.