For the making of this list I stuck to non-assassin classes (Irelia is up for debate, but I play her as a bruiser) and Juggernauts (unless pre-update) as well as about 30 kills and single digit deaths and normal/ranked games only (no aram, no custom, no AI). Anyone can go 99999/0 Katarina :P
Champion Used: Morgana
Total Time: 37 minutes 21 seconds
Score: 36/0/14
Champion Used: Ashe
Total Time: 50 minutes 53 seconds
Score: 30/6/16
Champion Used: Irelia
Total Time: 27 minutes 55 seconds
Score: 36/0/5
Champion Used: Rengar (Just because I went AP not assassin, have screenshot proof)
Total Time: 45 minutes 49 seconds
Score: 27/8/18
Champion Used: Nunu (mid)
Total Time: 41 minutes 59 seconds
Score: 28/6/12
Champion Used: Malzahar
Total Time: 54 minutes 5 seconds
Score: 45/11/3 (2 more deaths than single digit but a hell of a lot more kills, worth)
Feel free to add me on skype "Froggehman" or league of legends "Froggeh" if you want proof xP, that's all I've got saved!
Edited to make it easier to read xP