I married Brelyna.
Note to self: DO NOT TAKE HER HOOD OFF.

What, is she secretly Medusa and has snake hair?
My female character has married Belrand. He makes a great follower... although I sometimes have to take his magic staffs away, as he has a tendency to blast wolves with fireballs. He is SO protective.
Erik's the same way, less the staff. More than once I've been backpedaling away from a bandit, trying to heal myself before he hits me again, and then in comes Erik out of nowhere to save the day and squash the bandit flat.
...I can't let him have staffs though. I gave him a lightning staff once (to carry, not knowing followers auto-equip staffs instead of using their usual equipment). For ten minutes. Three electrocution incidents later, I took it back.

(He means well, but ranged damage is just not his thing. I keep finding his arrows stuck in friendly NPCs...like an incident in the Reach when, after a tough, frantic battle I stopped and realized Delphine had one of Erik's dwemer arrows sticking out of her posterior.

)
Re: Erandur... In my unmarried days he also accompanied me on many adventures. I was getting fond of him until I took him down to Blackreach. Then, suddenly he got really talkative, and went rambling on endlessly about how guity he felt about all the people he had killed and how he felt he was on the verge of losing his mind. He alarmed me so much I rushed him back to the surface world and released him from my service. Even then, he wouldn't leave and followed me around for 3 days like a lost puppy before he would return to his temple in Dawnstar.
Now see, that appeals to my character.

She likes fixing people's problems entirely too much. Erandur would fit that bill, and he's sweet and personable to her to boot. Trouble is I'm also totally attached to Erik at this point as well. First world Skyrim problems, man.