Did you check the spn_littlebro delicious account's (https://delicious.com/spn_littlebro) h=electrocution tag (https://delicious.com/spn_littlebro/h%3Delectrocution)? I know we have a lot of recs there (I also personally rec what anon suggested as well)

And here's my own recs:

Don't Let Go (http://www.fanfiction.net/s/4924056/1/Dont_Let_Go) by ChristianGateFan (http://www.fanfiction.net/u/722434/ChristianGateFan)
Summary: When the boys are captured by the first 'friend' Gordon sends after Sam, one with a vendetta of her own, things go horribly wrong. Did Dean come back from the djinn's near-perfect world, for Sam, just to lose him now? Much Limp!Sam and Protective!Dean.

Revenge is a Dish Best Served Cold (http://www.fanfiction.net/s/4915109/1/Revenge_is_a_Dish_Best_Served_Cold) by sammygirl1963 (http://www.fanfiction.net/~sammygirl1963)
Summary: Sam is kidnapped and tortured by a hunter for revenge against John. Will he survive until his family can find him? LimpSam/AngstyDean/AngstyJohn Warning: Language