Here are ranked the top 98 who played regular games by the number of kills per square root of number of games.

21.72 AmericanHist0ryX
14.14 Tsvototi
14.09 {A}Monkey SLayer
14.01 DO3
13.11 Intuition
12.70 hagadahae
12.49 wertrew
11.38 TimeR_rW
10.52 LololeRastA
10.50 Donald Krunk
10.48 stakaboo
9.76 DieNoobs
9.65 axlehammer
9.61 Jack Barrows
9.51 Oliversdad
9.19 gtoo
8.95 GodAlmighty
8.93 toms
8.92 NardSausage
8.86 Bomberman95
8.78 convolution
8.75 ahnbohwan
8.58 hankey
8.52 Grimbum
8.42 death-2-beepa
8.35 Adolvo
8.30 dragonfly500
8.25 Farles
8.14 vecker
8.12 warrior cat
7.96 arkenkor
7.69 Gummitarsan
7.66 avesano
7.61 Noob Slayer
7.61 REMCO
7.33 dwarf invasion
7.15 kolaps
6.93 Realize
6.93 integral
6.80 Karsten4130
6.54 probabler
6.50 IFIGENIUS
6.41 Lauch mit Schlau
6.21 Liptak
6.13 Captain Ramius
5.81 barry gateaux
5.73 miguelz262
5.60 Beach_Bum_13
5.59 ehervey
5.59 Dinnot
5.35 BAMMBI
5.27 Erathia
5.10 Hong Kong
5.03 Lil Johnson213
5.02 Magno 123
5.00 Vermont
4.96 Verano73
4.94 PureOdyssey
4.79 MNML
4.76 Louis Cypher
4.59 Genki_
4.58 ireneo
4.53 Adam Candee
4.40 Slam Masterson
4.35 spman
4.34 masticore
4.29 Puzzi
4.25 Last Stan Japan
4.21 junobeach
4.11 rofarah
3.97 GleepGlop
3.95 @iflagnstabnwin
3.95 Federer62
3.86 rushwing
3.52 Nerd Alert
3.49 piers plowman
3.35 Bart Lee
3.21 Cristiano917
2.96 burcin
2.94 Who'sNutz?
2.83 Axel_Kohlmann
2.79 Med1
2.77 Sersuke
2.65 8 8
2.62 Maze78
2.36 greeen
1.96 S3Z0
1.89 spman2
1.80 Lalita Lani
1.63 SHO-GUN
1.40 hisandherpes
1.22 baz cake
1.13 spman3
1.11 Grux
1.11 Soromon
1.11 CriticalDog
0.00 gtzlat
0.00 DonnieScribbles