What are the best exersizes for triceps? I currently do this:

Triceps
Single dumbbell overhead extension, both arms:
20kg x8 1set
22kg x8 1set
24kg x8 1set

DB Kickbacks
16kg x8 1sets
18kg x8 1set

Triceps Pushdown:
35kg x8 1sets
38kg x8 1sets
41kg x6 1 set
28kg x8 to failure