I'm running one for my sword and board Warrior that lets me use Mjölnir, and doesn't break the game. There are mods out there that don't ruin it, they're just buried under the oodles and oodles and oodles of stuff that *does* break the game.
Tell me about it. I was searching for a mod that would add some new bows to the game, but most of the bow mods are for insanely powerful bows - mainly ones with names like "ubber bow" ( yes, that's actually the name, down to the complete lack of capital letters ) which kill anything in the game in one hit.
I did manage to find some fun-sounding mods, though. I'm now using the following:
Frostfall, which is apparently a survival-type mod for cold environments. You can freeze to death, basically.
Hunting in Skyrim, which basically expands hunting and makes it a more interesting activity. It has perks and such.
Vanilla Archery Improved, which mainly increases arrow speed ( it always bothered me that arrows were so unrealistically slow ) and reduces the auto-aim.
As well as a few cosmetic mods ( more rain, more snow, more birds ).