All these other races have the options to get married , but after several playthroughs I still haven't found anyone that would let me marry them being I am an Argonian female.

Is there any mate for a lonely Shadow scale?

http://www.uesp.net/wiki/Skyrim:Derkeethus, http://www.uesp.net/wiki/Skyrim:Scouts-Many-Marshes, and http://www.uesp.net/wiki/Skyrim:Shahvee are all available for marriage.

Derkeethus also makes a good follower. He will level with you up until level 30 and he's the only follower in the game that is marked as an essential character, meaning that he is invincible and cannot die.

However, as long as he's not following you he has a strange habit of running back to Darkwater Crossing everyday to run his shop, even if you ask him to live with you. :\

Shahvee in Windhelm, Derkeethus in Darkwater Crossing.

Derkey as I call him is one of my favorite Argonian spouses and does make a fine follower when you give him a magic staff or two.

Derkeethus' essential status is a bug* and because of that bug, he will not stay at any home (or Sky Haven Temple) and will instead return to Darkwater Crossing; also, Darkwater Pass is a difficult dungeon for a low-level character. Scouts-Many-Marshes and Shahvee are fine stay-at-home spouses, but their quests are radiant and may not be accessible when trying to get them.**

*Before any one criticizes Bethesda over it, it's a very tiny, easily-missed bug that's connected to a good reason: Derkeethus is not essential by default, but his rescue quest makes him essential until it stops, and it won't stop until he reaches home -- it stops him from being killed on the way back to Darkwater Crossing, especially if the player leads him out the back door of the pass. He is also not the only essential follower -- Mjoll and Cicero are also essential.

**This can be solved by doing other quests of the same "type". That's a little vague, but I'll clarify if needed.

Cicero is an essential follower as well but yeah. Derkeethus is the best choice. I am married to Scouts-Many-Marshes and not really liking it.

And let it be a glitch that will never be fixed for Derkeethus is an awesome follower and one reason why I have him is because he is Essential. I hate having non-essential followers cause they get lost and die so easily.

Give him a Staff of Magnus and Sanquine's Rose. He'll be one happy fellow and will actually glitch.. He'll magically get two Staves of Magnus! Though the duplicate will vanish when you try to take it.

I'll have to try that. o.o