Not my favorite restaurant overall, but certainly my favorite restaurant for a quick lunch at work:

http://www.supertortas.com/

Only one location remains, and it is not close.

There was this little hole in the wall Chinese restaurant in Bolingbrook, IL that I used to stop at every chance I was in the area. It was take out only and the owner only knew 5 words of English but the food was spectacular. It closed about 10 years ago when an all you can eat buffet opened down the street.

Signatures in DC. Great Asian, easy walk to the theater. But worst of all, the owner, that &^%-er Abramoff, leaves a bad taste in my mouth even today.:mad:

Pioneer in fusion cuisine
 

http://www.eossf.com/

Not my favorite, but one of the first to really do Asian fusion well. I heard they sold the restaurant, and with the owner and chef changes, the quality declined.

Interesting that the website is still alive despite the restaurant being dead.

Kaigenro in Las Vegas -- was a inexpensive neighbourhood Japanese restaurant with authentic Japanese fare. Seems the entire strip mall in which it was located is to be torn down. Very sad.....

On Indian School Rd in Phoenix there was a great little dive for Philly cheese steaks. I think it was called Ricky's Big Philly. Went there once on a business trip and it was great. Unfortunately due to landlord issues it closed about 18 months ago. Damn shame.

I feel for the OP as I certainly do have a restaurant I wear a figurative black armband for.

It was called Hunan Garden and it was a Chinese restaurant in Rye, New York. It wasn't the best food, the space was dimly lit and far too large for their clientele (which is why they went out of business in April of 2003) but I loved it. Some of my earliest memories are from dining there with my family and we got takeout weekly. They made the best spicy noodles I've ever had (and trust me, in the last nine years I've searched far and wide for a replacement) and the staff were always friendly. I'll never find Chinese food as good :(

I've eaten there and really enjoyed it (on the company dime so the wine and dessert were always welcome)

The Good World Bar, on Orchard St. in New York. It was my neigborhood pub for ten years, and it closed down roughly the same time I moved out of the city.

It re-opened on Delancey, but it's just not the same thing when I visit the neighborhood.

BTW, it was EXCELLENT Swedish food, not the beer and heavy pours that kept me coming back. They were voted "best burger in NYC", and their innovative bunches were just fantastic. :(

I miss Basta Pasta in the North Beach neighborhood of San Francisco. It was an institution for years, then went down-hill, then closed some years ago. (The neighborhood has correspondingly changed, too.) A reminder that nothing lasts forever.

Though there is no shortage of good restaurants in Las Vegas, I used to love Renoir at the Mirage. One of my fondest food memories is flying there for dinner from Washington, D.C. when I heard that it was closing.

^ :D

My favorite restaurant in the world was Angeli Caffe on Melrose and Poinsettia in Hollywood. It closed earlier this year after being open since 1984. The owner is a locally famous chef and radio show host named Evan Kleiman. That was really sad. I actually was on the phone with Evan personally when she fit me in for my final Thursday (was a tradition to go on Thursdays) with my favorite waiter in the world, David, working.

http://www.angelicaffe.com/

Just to correct one minor point in your post: Bistro 110 actually gave 9 weeks' warning that it would close, which is somewhat unusual.

For us, its Sakura of Tokyo, in Naperville, IL
 

This is where my wife and I had our first meal when we were dating. She never had sushi or Japanese food before and love it. It became our regular spot, usually going once or twice a month. One particular day, about 4-5 years ago, we notice something was odd, the older couple that tended to the cash register and seated you were no longer there, the waitresses were all different, along with the sushi maker. Service was extremely slow, it took almost 2 hours for the meal to be completed. The food was good, no problem there, but it was no longer the same. We've never found out what happened to the previous owners or staff, but we certainly missed it. The restaurant is still there, and it appears that it has gone through 2 ownership changes. The couple of times we've tried it the menu was changed and it was no longer the same for us.

Luckily, we found another one nearby, Raku Sushi, that is just as good.
If anyone is familiar with what happened to the "original" Sakura of Tokyo, or know if they re-opened in another location, please PM me.

1. For once I agree with VasantN. The original Russian Tea Room in NY.

2. Cock n' Bull in LA, on Sunset. It was wonderful food, warm atmosphere, lots of memories of dates there.