After downloading Dawnguard, I noticed that the horses at the Riften stable were no longer showing the red label to steal when you put the cursor on them. Who could pass up a free ride? The only problem is they start heading back to Riften when you dismount. They do fast travel with you though. I won't complain because it seems a dragon always comes by and kills them, (at least they did the two times I bought one). So far no dragons. The horse in the Whiterun stable is stealable. I have not checked the other stables yet.

If you befriend the guy at the stable in Riften (done through a simple brawl), he lets you use his horses for free. To my knowledge, no other stable allows this.

EDIT
This was available in Vanilla too.

There are three free horses in the game

Frost: The Fastest

Shadowmere: the most difficult to kill

Arvak: Flaming horse you can conjure.

Thanks for the info, Seuern. That is exactly what I did using the Gloves of the Pugilist. Don't have much need to use them.

Ho ho, pro tip indeed!

This thread has saved me thousands in coin.

If you workout the stable hand's problems with Saphire you also get to ride those horses for free. Riften is one of the first places I go on any new build just so I can brawl with the stable owner and get the use of his horses. Generally, it better to use a loaner horse than own one, though there are occasions you wish the horse wouldn't wander off right away.

Riften horses are quite easily stealable, so there seems little need to worry about said brawl.

There are also "random" horses to be found about the world with no owner. These also walk away from the player when dismounted, but return when fast travelling to a location.

Horses really aren't that expensive anyway, not once you've logged a couple of hours playtime.

o_O

He's the fastest? Damn, I'd hate to see the slowest. Come to think of it, I have no clue where Frost even disappeared to on me.