Few Builds I've found to work very well

Katarina(mid): Katarina Build Guide : Your AP Katarina Du Couteau Resource (dont play with knives) :: League of Legends Strategy Builds

Elise(Jungle):Elise Build Guide : YoDaTV's Guide to Elise, Queen of the Jungle! :: League of Legends Strategy Builds

Lee sin(Jungle): Lee Sin Build Guide : YoDA's 2.2k+ ELO Lee Sin, God of the Jungle *UPDATED* :: League of Legends Strategy Builds

Shaco(Jungle)(still relevant): Shaco Build Guide : Shaco, Devil of Solo Q :: League of Legends Strategy Builds

Hope this can help some of you guys, read the full review because the build will change depending on the enemy team, but the general idea will not.

*If you know of some good builds/guides link them in the comments :D *