Ruth's Chris Steakhouse. It's not a Texan original, but that just makes it better. If I recall correctly, their porterhouse for two is essentially 6 steaks in one (literally). There should be one in Seattle and Bevell... I mean, Bellevue.
Or if you happen to be in Fort Worth, the Reata is a Texan original and quite good (but ask for rooftop seating... unless it is raining). Though... I think they may be lacking GIANT steaks that are also giant.
Of course, a good steak really isn't that hard to make at home (and at home you can determine the giantness of your giant steak). Taco the Octopus gives a great introduction and several useful tips:
http://www.8legged.com/ (it's under Deep Fried Live, "Steak!")
Regarding seafood, yeah, the west coast in general is amazing. Though for some reason I've never heard of soft shell crabs being a really big deal there. Hard shell crabs... mmm. The Crustacean's (in San Fran) one of the best, if I recall, for dungeness crab, and Moe's in Oregon is supposed to have some darn good chowder of the clammed persuasion (but I haven’t had it since I was 14ish, so I could totally be misremembering).
If you're coming to PAX I can show you the people at Pike Place Market who throw fish at one another.
The flying fishes of Pike's Place have become iconic around the country due to training videos. I recall the first time I heard of the place was at a Target in NorCal when I was 17.
EDIT: You know... maybe the forum needs a Foodee thread for this sort of delicious discussion.