Pick any three contiguous states, imagine you live in the middle one. “You know why it’s so windy here? Because <Other state 1> sucks, and <Other state 2> blows!”
Maybe states with very little wind are immune to this, but I’d bet they work it in on that rare windy day anyway.
Corollary: If you don’t like the weather in <This State>, wait a few minutes and it will change!
Edit: I didn’t really answer the OP. As a Texan, Oklahoma can die in the fires of Hell. Backward assed sons of bitches.
And everyone who lives in Upstate New York hates New York City.
Actually as a Texan I am a Texan first and only, Not American a Texan. We hate all the other States, all of them. Some are nice places to visit but dear og who could live there, when they could live in Texas.
How come Texas doesn’t fall into the gulf of Mexico? Because Oklahoma sucks.
To the. OP “The Colonies?” Be careful thems fightin words and we got guns, last time you tried that it didn’t work out so well, did it?
Just kidding
Capt
I wouldn’t call it a ‘rivalry’, so much as us Michiganders openly acknowledging the enormous suckitude that is Ohio, while Ohioans remain firmly in denial.
And Toledo.
What a miserable retread and misappropriation of our better joke.
Why is Oklahoma so windy?
Kansas sucks and Texas blows.
And sometimes three!
Why does Iowa have artificial turf on the football field?
So the cheerleaders don’t graze on the field after the game.
Why don’t they serve Kool-Aid in Wisconsin?
Because they haven’t figured out how to get two quarts of water in that tiny little package.
Why are there no volcanoes in Minnesota?
Because there are no virgins to sacrifice.
In Canada, there are rivalries between the cities of Montreal and Toronto. Montreal used to be the biggest city in Canada, but now Toronto is.
It’s customary of the rest of Canada to hate Toronto. Or Quebec. Or Alberta.
Vermont and New Hampshire, despite being the size of a large postage stamp between the two of them, could hardly be any different. New Hampshire thinks we’re a bunch of filthy hippies, and we think they are a bunch of backwards rednecks (which are called “woodchucks” in this part of the world).
Neither stereotype is completely accurate, but both, as usual, contain a certain amount of truth.
Well, there’s that whole North / South thing (with some people, anyways)
Locally, I keep living in cities where one side or the other (often the south side, ime) is less desirable to the other side. In OKC, it was them darn southsiders that gave the city a hick-doofus-inbreeder-redneck rep to outsiders. I live in a real small town in NM now, and the east side is filled with people you don’t want your daughter to date.
cough Alaska cough
Who does Alaska hate? Is it all Canadian jokes around there?
Which state doesn’t do this? Isn’t that why Kentucky and West Virginia exist?
Texas isn’t fond of Alaska because they lost their biggest state status to them. Alaskans joke that they’ll split into two states and make Texas the third largest.
Rhode Island has a rivalry with Delaware because we are the actual state based unit of measument. Rhode Island is so small it can’t be drawn to scale on maps. Even then you can’t discern the body of water surrounding our state.
Vermont and New Hampshire have a long time rivalry, something about who has the most miserable winters.
New York and New Jersey are long time rivals. Basically, Jersey is considered a low rent suburb of New York.
North and South Dakota had some kind of rivalry at the time of statehood. The single territory had too many people (really, that’s what they say), so it was split to become two different states. The president had the two bills shuffled at the signing so there wouldn’t be a way to determine which one was declared a state first.
Alabama and Mississippi have a long time rivalry over who is more stupid. They both reached 100% stupidity saturation long ago, so neither is more stupid than the other. However, all attempts to explain that to them have failed.
We’re much too Civil to have a War. 
I see mostly moral and ethical rivalries. Kansas vs. the nation abortion and women’s rights.
Texas vs. the nation on punishment, Arizona vs the nation immigration.
Maybe so, but Alaska jokes have shot up everywhere in recent years, since it spat Sarah Palin out on the rest of us.
Have to agree on that, I love living in Texas but dear og we here seem hell bent for leather on executing as many people as possible and rewriting History and Science books to make sure GOD did it all. I am fortunate to live in one of the few “blue seas” in an ocean of “red” could do without my Congresswoman though.
Capt
Texans hate Alaska for being the biggest state. (Texas was from 1845 until 1959.)
Alaskans like to threaten to split their state in two and make Texas the THIRD biggest state.
ETA: now most of us hate Alaska for giving us Sarah Palin.
rats. Ninja’d by Tripolar.
Delaware = sand fleas and chicken shit.
Speaking as a long-time Californian, we don’t care what any of you think of us! We’re hated, but probably cause you guys all suck! 
Though I do think that Texas and us have a sorta rivalry thing going, being the two most populous states. Hell if I give a damn about a Texan though! 
Texas is like a huge rabbit hutch, except the rabbits have guns.