Dogs.
Less Prep time, they can do more, they arnt dangerously big (Unless YOU are just tiny), they are just ADORABLE when they are ready to...um...Get up in you. There is lots of different breeds, so lots of Variety of Studs. Even if you dont get the knot, the whole experience is enjoyable.
And I still have very, VERY fond memories of loosing my V-Card to a HANDSOME Redbone Coonhound on the 4th of July.
And we fooled around several more times since then. When he was ready, he'd grab my leg with his strong forearms and try to trip me. Boy had a STRONG grip. And he was abit heavy, so it was hard to get him off when he was rearing to go....he was abit of a Dom Daddy, and I kinda liked it when he pins me down....
ANYWAY, Dogs.
Horses Im sure are fun, but I dont own a ranch or have friends that own horses, so Id have a much harder time trying....