During a recent cross country car trip I enjoyed touring the "downtowns" of cities large and small. Mant downtowns were depressing with mostly empty store fronts destroyed by Walmart and other big box retailers (and of course changing retail habits of the local population)

Other places had vital downtowns, not yet destroyed by the strips out side of town.

What cities large and small have the best downtowns?

Large: Tossup between New York and Chicago, frankly. I love them both. LA (the largest downtown near me) has an architecturally interesting downtown, but almost nothing to bring you there after dark (c'mon, does ANYONE really hang out around Staples Center?...), so it can't compete at all.

Smaller: Hmmm... The problem here is, most small- to mid-size cities are/were dependent on one or two major industries, and as the economy has lurched from favoring one sector to another to yet another, these cities' downtown areas suffer. Pittsburgh, for example, has an attractive downtown area, but the lack of good nightlife is killing it as an economic engine. I love San Diego, but parts of its downtown are ghost towns as new companies choose to settle in office parks outside the city itself-- which is a common occurrence killing downtowns throughout the US. In my hometown (Long Beach CA), there are great things happening downtown, but in small, highly concentrated pockets, surrounded by practically deserted office complexes. Kinda depressing.

Smaller would be Charleston, Asheville, Savannah or Athens.

GoTravel: Good suggestions! All nice cities.

My favorite ... Chicago

I like New York, like the previous posters - but if we can add Canada - I love Ottawa - VERY cool city, especially in the spring. Boston has some neat areas in it, as well.

I think Philadelphia has a lovely 'downtown.
Also-Montreal

I think for a big city, Chicago has a wonderful "downtown". Tons of things go on till late at night and lots of people are out. Toronto also has a very nice "downtown"

For small...Boulder and Fort Collins, Colorado. We live in Fort Collins and have the BEST "old town" down town. Also San Louis Obispo.

Oh my, I did forget about SLO! I adore that town-- I have to get back this summer for a day visit! Thanks for reminding me, Ani. And I concur-- fun li'l downtown area!

I also agree with Debi about Boston, Scarlett about Montréal (my folks lived there for 3 years, and it was magical for them), and Hipster70 about Toronto. Ahh, great towns.

For a small town downtown, I like Nevada City, Ca.

Another Canada...Halifas, Nova Scotia and Wolfville, Nova Scotia. Darmouth, NS used to have a lovely downtown (complete with a Woolworths) but it went downhill. It's hopefully on the mend though.

New York City, San Francisco, and Santa Fe.

I have visited many large cities through the years and would have to say that in my opinion the best downtown I have found is in Chicago. Both in quanity and quality of the stores. Marshall Fields is probably the nicest department store I have ever been in annnd I have found very little in other cities that can compare for shopping to the "Magnificent Mile".

Personally I think Seattle's downtown is fantastic for a smaller city. Tons of wonderful restaurants in all price ranges, lots of music venues, theaters, etc.

Portland OR has a nice and revitalized/ing downtown. Very walkable and interesting shops.

I second Santa Fe. Those that stand out in my head as being nice downtowns seems to be cities that have made an effort to revitalize or to restrict how their cities grew.

I hate to get people started on San Francisco but I think it has (or had) a nice downtown area where there was lots to see and do and walkable.

Admitting a bias, I vote for San Antonio. It's quite pretty and built on a human scale, very walkable, has lots of restaurants and shops, and a strong sense of history. All it lacks is a grocery store - but the terrific Central Market is not far away.

Naperville, IL. It's a small town, but they have done an outstanding job with their downtown, there is a mix of "mall" stores, like Pottery Barn, Willams-Sonoma, The Gap, Talbot's, etc, but they have also kept some antique stores & independent stores. Lots of restaurants, a riverwalk, can't beat it!

The comedian, WC Fields, once said, "once you leave New York, everyplace else is Philadelphia." How true.

San Luis Obispo has a good downtown for a small city. In fact I liked it so much I moved there.
For large cities New York has no equal but Chicago is good as well as Boston.