Here are the top 100 ranked by kills per root game.

KPRG Player
13.68 KingRussy
13.01 pipacs
12.62 Brennwert
12.06 Noobie
11.95 mar101
11.10 OneShot7
10.65 spanky6
10.14 ovbogaert
9.95 michele
9.93 GRRRRR2
9.71 kaiosezzar
9.45 Darek Szewczyk
8.55 Hong Kong
8.51 isaaktas
8.47 CzarciSrom
8.36 Beach_Bum_13
7.99 champion22
7.70 fuzzymcfuzz
7.61 Rastaa Man :)
7.43 arkenkor
7.42 Hunken
7.04 LololeRastA
6.89 Pekonens
6.60 lipos
6.52 Torudelli
6.32 sews4wampum
6.24 kolaps
6.23 Donald Krunk
6.22 rocka09
6.19 michl
6.00 Tate73
5.98 Creepy Dude
5.63 si82
5.56 john_egg
5.42 madlamb
5.38 AYBG
5.35 procutter
5.32 Gurg1
5.27 integraI
5.26 fluxboxer
5.18 _main_
5.03 Qaziyev
5.00 IFIGENIUS
4.97 hcdug
4.83 masticore
4.82 Smoke Two Joints
4.82 Nerd Alert
4.77 AIex
4.75 stakaboo
4.69 rofarah
4.69 ChalkdustTorture
4.67 Amoos
4.61 Mr.Mosgood
4.60 alex_sfb
4.58 twiga
4.56 spman
4.56 longpube
4.32 thegreenheaven
4.25 ehervey
4.17 22 Apr
4.15 villalobster
4.08 1st.skyler
3.96 k?lllll
3.94 MariquitaPower
3.93 ireneo
3.81 Whitehawk
3.74 Noob Slayer
3.64 Dude111
3.55 franklyghost
3.54 RyanIsntLife
3.53 objecta2
3.52 iDu
3.41 vicsf
3.37 Fats939
3.34 THRILLHO
3.22 no_name2
3.20 BenJa LeZana
3.16 osiriswaris
3.13 tincolor
3.10 kdiceplaya!
3.04 moulue
2.93 fish28
2.86 OverNow
2.65 apignarb
2.65 parsifal
2.43 Kingofskillz
2.41 Nippelking
2.38 bebel
2.38 aforb
2.23 Brighty
2.00 Kdo
2.00 masterDD
1.83 Ninjamonkey
1.77 spman2
1.74 Kekko2797
1.66 Benjamin Videz
1.60 icanofer
1.26 PRESIDENT N° 1
0.95 Voo
0.00 jurgen