Here are the top 100 ranked by kills per root game (excepting Yll, Jurgen, and elvissey, who played no regular games):

13.00 Brennwert
12.78 wertrew
12.50 Drucifer85
11.44 Hennessy
10.87 Noobie
10.76 Tarilonte
10.42 DO3
10.22 MWixxx
10.21 Zard0z
9.63 Beach_Bum_13
9.58 Gurg1
9.42 madlamb
9.03 pdtkdt
9.03 kaiosezzar
8.93 Help, I'm a rock
8.67 cadpilot
8.47 integraI
8.37 jf220
8.35 stakaboo
8.33 mrlee
8.20 BashTime
8.20 mreinwald
7.93 slyner
7.71 the die
7.67 Maze78
7.48 michele
7.42 hcdug
7.31 Hobyandy
7.24 chiefChief
7.14 Marcysch
7.09 uolter
7.02 TheSwiper
7.02 Juhokki
6.98 Rafkrik
6.98 Egazas
6.89 panzer
6.80 isaaktas
6.40 Pedda
6.31 ghj luigi
6.28 vicsf
6.26 Crashz
5.98 edinbro
5.81 shadolin
5.71 thegreenheaven
5.66 Kerberus
5.60 prymus
5.51 Riles P
5.42 Vasha9276
5.34 WarPig11
5.23 lipos
5.04 negramarta
5.03 Ttoronto
5.01 k?lllll
4.95 IFIGENIUS
4.91 parsifal
4.89 potato27
4.85 Andrew_Mullek
4.85 bcmatteagles
4.81 procutter
4.69 vino_en_carton
4.65 Sensei_Mata
4.57 Slinus
4.37 LostMurti
4.29 Bart Lee
4.05 1a2b
4.03 Tate73
3.98 ehervey
3.93 Mexx79
3.91 Skerdikas
3.91 Jan Paul Kraemer
3.89 zlOko
3.73 Maser
3.68 pooch723
3.65 Greenhorn91
3.53 kittensmeow
3.25 beevoh
3.25 moulue
3.08 ch1c0_3v0
3.06 63 belly
3.06 Bombardier DS 65
3.03 PureOdyssey
2.94 Lil Johnson213
2.84 Soromon
2.78 PRoCc
2.54 Nippelking
2.48 Imganja
2.42 apignarb
2.25 franklyghost
2.14 longpube
1.78 Voo
1.57 PRESIDENT N° 1
1.57 Sturmhardt
1.54 Fonias
1.20 NikkeKnatterton
0.89 Jo-Joo
0.67 EvAngelion27
0.00 special k dice