If I may straddle the fence, thereby setting myself up for abuse from both sides, I think any argument of whether Chicago or the West Coast has more going for it as a culinary mecca is fun, but silly.
I was born and raised in Chicago. I lived in L.A. for six years. I returned and have lived in Chicago for just over another four. And the truth is that both have their strengths, and I could not reside in either city without missing certain culinary items that the other features. I'm not nearly Mexican-savvy enough to have any informed discussion with this crowd, so I'll leave that one alone entirely

But that aside, here's how I feel:
When I was living in L.A., I missed the obvious candidates: Italian beef, Chicago-style dogs, deep dish pizza, etc. I missed Greektown. I missed P.S. Bangkok and Walker Brothers and Bale. I don't have a lot of familiarity with German and Polish, but if I did, I'm quite certain I would have missed them, too.
But now that I'm back in Chicago, I miss an awful lot about L.A. I miss In 'n Out. I miss shabu shabu (though I hope and pray that Matsumoto's recent revelation will change that). I miss the fact that every corner sushi bar in L.A. served great fish, whereas Chicago necessitated hunting down a couple of select spots (though thankfully, this seems to be changing). I miss the delis... not that L.A. is anything like N.Y., of course, but they're still a big head and shoulders above Chicago in that department. Generally speaking, I miss the incredible quality and freshness of the produce. I REALLY miss West Coast Cantonese. When it comes to Sichuan, the West Coast can kiss Tony's ass (Lao Sze Chuan), as far as I'm concerned, but I still haven't found Cantonese seafood in Chicago that makes me happy, despite numerous recommedations. I really, really miss the tuna melt at Bob's 49. And though I admittedly have impossibly exacting standards for trattoria-style Italian, I haven't yet had anything in Chicago that can match Da Pasquale in Beverly Hills.
Point being, as a food lover who has split his adult life between L.A. and Chicago... almost to the month... I absolutely couldn't say, culinarily, that I favor one or the other. I mean, there's no question that I GENERALLY favor Chicago... it's why I moved back and intend to stay

... but I think that residents of either place crowing culinary superiority over the other are either underinformed or, understandable as it may be, letting objectivity take a backseat to civic pride.
If I could just bring ALL of the restaurants here