Tacoma and the eastern side of DT Vancouver, in that order. Parts of LA like old warehouse districts along I-5 are nasty too. Parts of the Bay Area are dingy too.
To me it seems like every major metro on the west coast has some pretty bad spots, except maybe San Diego? I've only been there once in my life so I don't know, maybe it has some 'Navy Grit'. Portland 20 years ago was pretty gritty, but determined effort at urban renewal has changed a lot of that, now the buildings and streets are clean... but the people don't know what a shower is
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Tacoma to me, if you take it the mountains and hills away, could be any gritty Great Lakes city.