All time topscorers in CL knock-out matches.

28: Lionel Messi (Barcelona)
20: Cristiano Ronaldo (Real Madrid, Man United)
18: Raúl (Schalke 04, Real Madrid)
17: Andriy Shevchenko (Chelsea, Milan, Dynamo Kiev)
16: Filippo Inzaghi (Milan, Juventus)
15: Frank Lampard (Chelsea)
14: Wayne Rooney (Man United)
13: Didier Drogba (Chelsea, Marseille)
12: Thierry Henry (Barcelona, Arsenal, Monaco)
10: Kaká (Real Madrid, Milan)
9: Fernando Morientes (Valencia, Liverpool, Monaco, Real Madrid), Alessandro Del Piero (Juventus), Samuel Eto'o (Inter, Barcelona, Mallorca)
8: Mario Gómez (Bayern Munich, Stuttgart), Arjen Robben (Bayern Munich, Real Madrid, Chelsea, PSV), Michael Ballack (Chelsea, Bayern Munich, Bayer Leverkusen), Jari Litmanen(Ajax, Liverpool), Zinédine Zidane (Real Madrid, Juventus)
7: Diego Milito (Inter), Ivica Olic (Bayern Munich, CSKA Moscow)
6: Emmanuel Adebayor (Real Madrid, Arsenal, Monaco), Giovane Élber (Lyon, Bayern Munich), Ruud van Nistelrooy (Real Madrid, Man United, PSV), Steven Gerrard (    Liverpool), Sylvain Wiltord (Lyon, Arsenal, Bordeaux), David Trezeguet (Juventus, Monaco), Karim Benzema (Real Madrid, Lyon), Ryan Giggs (Man United), Fernando Torres (Chelsea, Liverpool)

Per nationality
5: France
3: England, Spain
2: Argentina, Italy, Brazil, Germany, Holland.