Serious Eats - seriouseats.com

Cheese cake - shoot me. I've just never been crazy about it or for that matter, any dessert made with cream cheese.

This is a challenge even for natives as we tend to conflate the two, and Tex-Mex is so very well-established here. But there are few places for sure that are not all about the border:
Cafe San Miguel on Henderson in E Dallas and Gloria's (chain) both offer Tex-Mex alongside traditional Mexican and Latin American fare.
Ciudad and La Duni on Oak Lawn; upscale fusion-y Latin and Mexican fare
Seafood: El Pulpo on Live Oak -
Javier's: Mexico-City Mexican in Park Cities.
Veracruz in Oak Cliff
The DallasNews.com Web site lists over 600 "Mexican" restaurants across the DFW area. It's a good place to start with reviews and maps...

Icing with way too much sugar. I'm usually the one scraping icing off of cake at parties.
Banana bread or cooked bananas (plantains don't count). I love bananas though.
Most corporate baked goods; you can taste the lack of love and care in them, and I can't remember ever reaching for carrageenan or sodium benzoate when baking.
Sugar-free anything. Sugar substitutes taste nasty.
Most fruitcakes. I'm bored with them.
Adult-sized slices of chocolate cake. I usually find it too rich to eat in large quantities. I love chocolate, I just prefer it in small doses.
Most donuts, except for cake donuts.
Crunchy cookies. Just not a fan of the texture.

Desserts that make me go meh:
Red velvet cake? I mean, it usually tastes OK (vaguely reminiscent of malted milk, like Wendy's frosties), but I always feel odd eating so much food coloring.
Sock-it-to-me/7-up/insert soda here cake. Common in Southern cooking, and almost always too sweet.

Re: buttercream icing: unless you had it on a homemade cake or cake from a wedding party, it probably wasn't made with real butter. 'Buttercream' icing made from vegetable shortening is pretty disgusting.

I'm surprised so many people here don't like tiramisu, but I've had my share of bad tiramisu. I'll second the cannoli though. Highly overrated and just not that tasty.

Any flavor of chiffon anything.

i don't care for boozy desserts or vanilla ice cream.

I like most desserts but I hate it when they put the decorative raspberry liquid stuff around the plate and I get it on my chocolate cake. I don't like raspberry anything-those tiny little seeds irritate me. I rarely meet a dessert that I don't like.

Cheap, nasty grocery store cakes, anything with fake "whipped topping" or that contains the same ingredients as whipped topping, you know the roof of the mouth coaty stuff. I also agree with the artificial sweeteners on principal, as far as I know I've never eaten an artificially sweetened dessert and I hope I never do, if it comes to that I'd rather just have plain fruit.