So I'm playing through Skyrim with my new argonian dragonborn and I'm trying to keep him as IC as possible. I've recently decided he should get married, but the only argonian female really doesn't do a whole lot for me as she seems pretty cookie cutter. My question is, would it make sense from an in character perspective for an argonian to marry outside his species and if so what species would he marry?

Love knows no bounds.
Sure it would make sense if you invent a good backstory or love at first sight.
You should marry the one you like best, except possibly a racist Stormcloak.

I don't think the game cares what race you marry, so you just need to find the NPC that appeals to you, of the ones you can marry, and initiate the marriage process.

That is a good question....Argonians are "cold-blooded" egg layers and it would be a very one sided relationship if one were to marry a "warm-blooded" live birth type mammal. However,this being Nirn....who's to say a mutually beneficial relationship couldn't develope between the two. I have a Khajiit who married Lydia mostly to have her open a store in Breezehome so he could collect a little "travelling money" from her every week!

Argonians are unlikely to be exothermic due to their size.
They are likely facultative endotherms or endotherms. They wouldnt be able to function otherwise due to having to bask six hours a day.
They also are not (fully) egg-laying, this is dependant on environment.
In a cold and hostile place they will give live birth while in a safe environment closer to the Hist they will lay eggs.

I'd like to think that relationships are about more than just "friends with benifits". I'd think that any race could find happiness with another regardless of genetic compatibility. My question was more about if such a union would be persued by an argonian or if they'd be more against it. From what I've read about lore argonians don't really hold much against any race save for maybe the dunmer who enslaved them for years (My character doesn't like dunmer at all and usually agrees with the stormcloaks about them to some degree because of the past events in morrowind).

I like the idea that love knows no bounds, so the more challenging the couple, the more beautiful the outcome from an aesthetic perspective.

It all really depends on your character. My Khajiit is happy to be Ysolda's Khajiit lover (It's okay Ysolda... your secret is safe with me XD)

It would be funny to roleplay an exothermic Argonian and spend an hour or so basking after every physical exertion in the game.

You could put a good word in for her with those caravans she is so interested in

She does love the furry

I have 2 female Khajiits, one married a Khajiit male I added with a Nexus mod. the other is single but will likely marry a Nord male. I have a female Orc who married a Nord gal who owns a home and runs a mine. Seemed beneficial on many levels. My orc doesn't share the "all female Orcs for one chief" idea.

All my other characters are Nord and married a Nord... nothing interesting there though one is a werewolf

Think this could help...perhaps. Although Argonians are bound to the Hist... and for a people with a "hive mind" i doubt they would "fall in love" outside of their species. oh and it is stated Argonians are warm blooded in lore....

Notes on Racial Phylogeny

After much anolysis of living specimens, the Council long ago determined that all "races" of elves and humans may mate with each other and bear fertile offspring. Generally the offspring bear the racial traits of the mother, though some traces of the father's race may also be present. It is less clear whether the http://elderscrolls.wikia.com/wiki/Argonians and http://elderscrolls.wikia.com/wiki/Khajiit are interfertile with both humans and elves. Though there have been many reports throughout the Eras of children from these unions, as well as stories of unions with daedra, there have been no well documented offspring. Khajiit differ from humans and elves not only their skeletal and dermal physiology -- the "fur" that covers their bodies -- but their metabolism and digestion as well. Argonians, like the dreugh, appear to be a semi-aquatic troglophile form of humans, though it is by no means clear whether the Argonians should be classified with dreugh, men, mer, or (in this author's opinion), certain tree-dwelling lizards in http://elderscrolls.wikia.com/wiki/Black_Marsh.
The reproductive biology of orcs is at present not well understood, and the same is true of goblins, trolls, harpies, dreugh, tsaesci, imga, various daedra and many others. Certainly, there have been cases of intercourse between these "races," generally in the nature of [censored] or magickal seduction, but there have been no documented cases of pregnancy. Still the interfertility of these creatures and the civilized hominids has yet to be empirically established or refuted, likely due to the deep cultural differences. Surely any normal http://elderscrolls.wikia.com/wiki/Bosmer or http://elderscrolls.wikia.com/wiki/Breton impregnated by an orc would keep that shame to herself, and there's no reason to suppose that an orc maiden impregnated by a human would not be likewise ostracized by her society. Regrettably, our oaths as healers keep us from forcing a coupling to satisfy our scientific knowledge. We do know, however, that the http://elderscrolls.wikia.com/wiki/Sload of http://elderscrolls.wikia.com/wiki/Thras are hermaphrodites in their youth and later reabsorb their reproductive organs once they are old enough to move about on land. It can be safely assumed that they are not interfertile with men or http://elderscrolls.wikia.com/wiki/Mer.
One might further wonder whether the proper classification of these same "races," to use the imprecise but useful term, should be made from the assumption of a common heritage and the differences between them have arisen from magickal experimentation, the manipulations of the so-called "http://elderscrolls.wikia.com/wiki/Ehlnofey," or from gradual changes from one generation to the next.

I've never seen anything stating the Argonians are a hive mind. They're connected to the Hist but I don't think it goes quite that deep. I'd think the Hist is more of a religion based around a natural connection with the Hist trees rather than all Argonians being linked to one another.

My Orc is in wedded bliss with Aela.

My Orc is married to a nord gal too. I like to think of them as that couple that argues and picks on eachother endlessly, but if anyone were to even think of hurting her wife, well.. lets just say there's no empire, deity, or legion of dragons that would be able to protect that person from the wrath of the enraged Orc woman of which will be the last thing they ever see.

Exactly. Which is why I'm looking forward to Hearthfire on the PC cause I hear your wife can get kidnapped. And for me the same six marriage between my female Orc and the girl made sense. There would be no offspring which is fine. As mentioned an Orc woman would be ashamed and hide her child if one was born from a male of another race. I just couldn't match her with a male I thought would work. But yeah touch one hair on her head or look at her the wrong way and you'll have the scariest looking Orc Werewolf bezerker destroying the world to get her hands on you.

Interesting how the TES lore states that racial mixing between humans and elves occurs, but you never meet any "halfbreeds" they all look like pure race stock.
It is understandable that kitties and lizards would only be able to reproduce among themselves...but orcs?...

Orcs are Mer too!

Orcs have a fierce sense of pride. mixing with another race is like thinning their warrior blood. No Orc openly admits to having children with another race. lore has it that the act of re-production with orcs is far from romantic to say the least... lol