The whole "moron" oxymoron pun is just a bit too easy.

Some friends like to hang out together, get high and party. Some play salacious drinking games. Some like to hold upmarket dinner parties.
But not my friends.

We like to watch films about superheroes, play the odd LAN game of Age of Empires III, and have lengthy discussions on grammar.

The following text comes as a result of the latter.

Whoever invtented the word "oxymoron" is a...

I'm not going to bother finishing that sentence.

Dictionary.com defines an oxymoron as: a figure of speech by which a locution produces an incongruous, seemingly self-contradictory effect, as in “cruel kindness” or “to make haste slowly.”

Now here is the problem.
On closer inspection you will notice that both these examples are SHIT.
Okay, so maybe for a second I might be able to believe "cruel kindness" but we already have the phrase "sometimes you have to be cruel to be kind" making "cruel kindness" utterly useless.

But "To make haste slowly"
I'm sorry, what?
That just doesn't make any sense.

The best examples wikipedia can give as are, by it's own admission, either horrible cliche's or phrases designed specifically to be paradoxical:

Irregular Pattern
Deafening silence
Forward retreat
Friendly Fire
Jumbo Shrimp
Peaceful War
Quiet Riot
Serious Joke
Silent Scream
Sweet sorrow
Living dead

The reality is there are no good examples of oxymorons.

Almost all the "oxymoron example" lists you can find on Google contain examples that are simply words that are taken out of context, for exmaple:

Pretty ugly (here it is being implied that pretty is being used as a synonym for good looking, but it isn't in this context)

The best my A-level English teacher (a highly knowledgable lingistic) could come with were:

Bittersweet (which is just a word on it's own, and therefore inelligable for the title of oxymoron)

and

Icy heat (which suffers from the "err, what?" problem)

Oxymoron is a word that has been invented to describe something that virtually doesn't exist, and in fact the only use for it now is to make cynical post-modern jokes like:

Isn't "good Robbie Williams song" a bit of an oxymoron" [extended chortle].

Oxymoron, I officially hate you and everything you stand for.